WOOD 

AND  OTHER 

ORGANIC  STRUCTURAL 
MATERIALS 


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WOOD 

AND  OTHER 

ORGANIC  STRUCTURAL 
MATERIALS 


BY 
CHARLES  HENRY  SNOW,  C.  E.,  Sc.  D. 

DEAN    OF   THE    SCHOOL    OF    APPLIED    SCIENCE,    NEW    YORK    UNIVERSITY 
MEMBER  OF  THE  AMERICAN  SOCIETY  OF  CIVIL  ENGINEERS,  ETC. 


FIRST  EDITION 


McGRAW-HILL  BOOK  COMPANY,  INC. 

239  WEST  39TH  STREET.    NEW  YORK 


LONDON:  HILL  PUBLISHING  CO.,  LTD. 

6  &  8  BOUVERIE  ST.,  E.  C. 
1917 


A<\ 


COPYRIGHT,  1917,  BY  THE 
MCGRAW-HILL  BOOK  COMPANY,  INC. 


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f  -  '   .  *>  *  *"  \ 


THE  MAPLE  PRESS  YORK  PA 


PREFACE 

The  purpose  of  this  book  is  to  present  general  as  well  as  phys- 
ical characteristics  of  a  group  of  structural  materials,  most  of 
which  are  of  organic  origin.  Among  the  materials  thus  described 
are  woods,  paints  and  varnishes — with  their  associated  oils,  pig- 
ments, gums,  and  resins — glues,  creosotes,  and  indiarubber.  As 
stated,  most  of  these  materials  are  of  organic  origin.  Those  that 
are  not,  such  as  pigments  and  creosotes,  have  been  added  because 
of  their  close  practical  association  with  the  others. 

The  book  is  designed  for  engineers,  architects,  students  in 
schools  of  technology,  teachers  of  manual  training  and  others 
who  use  the  materials  described  or  who  are  interested  in  their 
properties. 

A  statement  of  the  reasons  for  separating  structural  materials 
along  the  line  of  organic  and  inorganic  origin,  seems  to  be  in 
order.  First,  this  basis  is  convenient:  in  fact,  so  many  of  the 
important  organic  materials  are  used  in  connection  with  one 
another  that  most  of  the  present  book  might  easily  appear  under 
such  a  title  as  "Properties  of  Woods  and  Associated  Materials 
of  Construction";  and,  in  the  same  way,  the  principal  inorganic 
materials,  steel,  stone  and  concrete,  are  commonly  associated. 
Second,  the  basis  suggested  is  logical:  organic  materials  are 
fundamentally  different  from  inorganic  materials,  for  the  former 
are  results  of  physiological  processes  and  have  within  them  the 
influence  of  life;  these  materials  may  manifest  variations  and 
special  traits  which  do  not  appear  in  the  more  homogeneous  and 
constant  materials  of  the  inorganic  group.  Assuming  that  some 
form  of  classification  is  desirable,  where  subject  matter  is  as  ex- 
tensive as  that  within  the  present  field,  the  writer  ventures  to 
urge  the  merits  of  the  one  now  employed.  Also,  a  book  devoted 
especially  to  the  materials  here  considered  seems  warranted.  It 
is  true  that  the  inorganic  materials,  metals,  stones,  and  concrete, 
upon  which  principal  attention  is  so  often  bestowed  in  text-books, 
do  predominate  in  the  larger  engineering  structures;  but  it  is 
equally  true  that  the  organic  material  wood  predominates  in 
other  structures,  and  that  some  of  the  materials  now  considered 

v 

365844 


vi  PREFACE 

are  used  in  practically  all  structures  with  which  the  engineer  has 
to  do. 

The  opportunity  is  taken  to  criticise  the  degree  of  emphasis 
often  laid  in  text-books  upon  those  properties  of  structural  mate- 
rials which  relate  to  strength.  That  this  phase  of  the  subject 
should  be  given  precedence  is  beyond  all  question,  but  that  it 
should  ever  be  emphasized  so  greatly  as  to  diminish  or  more  or 
less  replace  attention  which  might  otherwise  be  given  to  other 
features,  such  as  durability,  is  questioned.  In  other  words,  it  is 
regarded  as  pedagogically  unfortunate  when  the  whole  story  can- 
not be  at  least  outlined  to  the  student,  when  one  part  is  detailed 
to  such  an  extent  that  the  other  parts  cannot  be  detailed  at  all. 
The  belief  is  expressed  that  many  students  in  schools  of  tech- 
nology do  not  realize  as  early  as  they  should,  how  real,  live,  and 
practical  the  subject  " Properties  of  Structural  Materials"  is,  and 
how  greatly  knowledge  of  it  will  influence  works  which  they  may 
later  design  and  construct,  and  that  one  cause  for  this,  in  the  case 
of  some  students,  is  the  slight  or  omission  here  referred  to. 

The  printed  sources  of  information  employed  are  acknowledged 
in  footnotes  throughout  the  text,  and  in  a  bibliography  arranged 
for  those  who  wish  further  information  on  any  of  the  parts  in 
question.  In  addition  to  these  printed  sources  of  information, 
the  writer  is  deeply  indebted  to  some  who  have  assisted  him  with 
special  information  and  with  criticisms  and  now  acknowledges 
assistance  thus  received  from  Professors  W.  Kendrick  Hatt, 
Hermann  von  Schrenk,  C.  Stuart  Gager,  Charles  P.  Sigerfoos, 
Edgar  W.  Olive,  Alvah  H.  Sabin,  the  late  Charles  E.  Bessey,  and 
the  late  Mr.  Octave  Chanute,  past  president  of  the  American 
Society  of  Civil  Engineers.  He  also  thanks,  among  others,  Mr. 
C.  D.  Mell,  Acting  Dendrologist  of  the  United  States  Forest 
Service,  Mr.  Charles  A.  Hexamer  of  the  National  Board  of  Fire 
Underwriters,  Mr.  Norman  Taylor  of  the  Brooklyn  Botanic  Gar- 
den, Mr.  Edward  A.  Hewitt,  late  chemist  of  the  Cooper  Glue 
Company,  Dr.  Lothar  E.  Weber,  of  the  Boston  Indiarubber  Labo- 
ratory, and  several  of  his  colleagues  in  New  York  University. 

CHABLES  H.  SNOW. 

UNIVERSITY  HEIGHTS,  BRONX, 

NEW  YORK  CITY, 

June  1,  1917. 


TABLE  OF  CONTENTS 

PAGE 
PREFACE    v 

INTRODUCTION 

Practical  Value  of  Subject  "Properties  of  Materials."  Materials 
Divided  into  Organic  Materials  and  Inorganic  Materials;  Basis  for 
this  Division.  Conservation.  Relation  of  Organic  Materials 
to  Conservation xvii 

CHAPTER  I 

WOODS  COMPARED  WITH  STONES  AND  METALS.     NOMENCLATURE. 
FUNDAMENTAL  CLASSIFICATIONS 

Comparisons.  Consumption  of  Wood.  Reasons  for  Preferring  Wood. 
Uses  of  Wood.  Common  and  Botanical  Names.  Classifications: 
Botanical  Classification  of  Trees  and  Woods;  Gymnosperms  (Coni- 
ferse)  and  Angiosperms  (Monocotyledons,  Dicotyledons) ;  Practical 
Classification  of  Trees  and  Woods;  Banded  Trunks  and  Woods 
(Coniferous  Series,  Broadleaf  Series);  Non-Banded  Trunks  and 
Woods .  1 


CHAPTER  II 

TREES.     PHYSIOLOGY  OF  TREES.     VALUE  OF  FORESTS.    FORESTRY 

Trees  Considered  as  Sources  from  which  Woods  are  Derived.  Physi- 
ology of  Trees:  The  Root  System;  The  Leaves;  The  Trunk  (Length- 
Growth,  Thickness-Growth,  The  Cambium,  Sap  Movement,  In- 
fluence of  Sunlight).  Value  of  Forests  (Humus,  -Influence  of 
Forests  on  Streamflow,  Influence  of  Forests  on  Erosion).  For- 
estry   

vii 


viii  TABLE  OF  CONTENTS 

CHAPTER  III 

PAGE 

WOODS.     CHARACTER  AND  ARRANGEMENT  OF  WOOD-ELEMENTS.     IN- 
FLUENCE   OF    CELLULAR    STRUCTURE    UPON    CHEMICAL 
COMPOSITION  AND  PHYSICAL  PROPERTIES  OF  WOODS. 
IDENTIFICATIONS.    STATEMENT  OF  WEIGHTS 
AND  MODULI  EMPLOYED  IN  TABULAR 
DESCRIPTIONS  OF  SPECIES 

Definitions.  Cellular  Structure  of  Wood.  Importance  of  Subject. 
Wood-Elements:  General;  Wood-Fibers;  Tracheids;  Vessels;  Wood- 
Parenchyma  Fibers;  Pith-Rays  (Forms,  Functions);  Resin-Canals 
(Resins) ;  Arrangement  of  Wood-Elements;  Associated  Compounds; 
Influence  of  Cellular  Structure  upon  Chemical  and  Physical 
Properties  of  Woods.  Identifications.  Statement  of  Weights  and 
Moduli  Employed  in  Tabular  Descriptions  of  Species 17 

CHAPTER  IV 

BANDED  TRUNKS  AND  WOODS.     GENERAL. 
(Conifers  and  Dicotyledons) 

General.  Parts  of  the  Trunk:  Wood-Elements;  Annual  Layers  (Spring 
and  Summer  Deposits,  Means  of  Determining  Age,  Means  of 
Identification);  Bark  (Inner  Bark,  Living  Bark,  Corky  Layer, 
Epidermis):  Sapwood;  Heartwood;  Pith.  Development  (Cross, 
Radial,  and  Tangential  Surfaces,  Grain  or  Figure,  Definitions). 
Defects  (Shakes,  Checks,  Knots,  Disease,  Manufacturers'  Stand- 
ards). Sub-Divisions:  Coniferous,  Needleleaf  or  Softwood  Series; 
Non-Coniferous,  Broadleaf  or  Hardwood  Series .  .  . 34 

CHAPTER  V 

BANDED  TRUNKS  AND  WOODS  (Continued) 
Coniferous  or  Needleleaf  Series  (Conifers) 

General  and  Introductory.  Pine:  The  Soft  Pines  and  Hard  Pines 
(White  Pine,  Sugar  Pine,  Georgia  Pine,  Cuban  Pine,  Shortleaf 
Pine,  Loblolly  Pine,  Bull  Pine,  Norway  Pine,  Pitch  Pine,  Northern 
Pine,  etc.,  etc.).  Kauri  Pine  (Kauri  Pine).  Spruce  (Black  Spruce, 
White  Spruce,  Sitka  Spruce,  etc.).  Douglas  Spruce  (Douglas 
Spruce).  Fir  (Balsam  Fir,  Great  Silver  Fir,  Red  Fir,  White  Fir, 
Noble  Fir).  Hemlock,  (Hemlock  Western  Hemlock).  Larch  or 
Tamarack  (Larch).  Cedar  (Red  Cedar,  Juniper,  White  Cedar, 
Canoe  Cedar,  Port  Orford  Cedar,  Yellow  Cedar,  Incense  Cedar, 
etc.).  Cypress  (Bald  Cypress).  Redwood  (Redwood,  Giant 
Redwood)  .  44 


TABLE  OF  CONTENTS  ix 

CHAPTER  VI 

BANDED  TRUNKS  AND  WOODS  (Continued) 

Broadleaf  Series,  Part  One  (Dicotyledons) 

PAGE 

General,  Definitions.  Oak  (White  Oak,  Cow  Oak,  Chestnut  Oak, 
Post  Oak,  Bur  Oak,  Western  White  Oak,  Red  Oak,  Pin  Oak, 
Spanish  Oak,  Black  Oak,  Live  Oak,  California  Live  Oak,  English 
Oak,  etc.).  Ash  (White  Ash,  Red  Ash,  Blue  Ash,  Black  Ash, 
Green  Ash,  Oregon  Ash,  etc.).  Elm  (White  Elm,  Cork  Elm,  Slip- 
pery Elm,  Wing  Elm,  etc.).  Maple  (Sugar  Maple,  Silver  Maple, 
Red  Maple,  Oregon  Maple,  Box-elder,  etc.).  Walnut  (Circassian 
Walnut,  Black  Walnut,  White  Walnut,  etc.).  Hickory  (Shagbark 
Hickory,  Pignut,  Mocker  Nut,  Pecan,  etc.).  Chestnut,  Chinqua- 
pin (Chestnut,  Chinquapin,  etc.).  Beech,  Iron  wood  (Beech,  Iron- 
wood,  Hop  Hornbeam,  etc.).  Sycamore  (Sycamore,  California 
Sycamore,  etc.).  Birch  (White  Birch,  Paper  Birch,  Red  Birch, 
Yellow  Birch,  Sweet  Birch,  etc.).  Locust,  Mesquite  (Black 
Locust,  Honey  Locust,  Mesquite,  etc.) 102 

CHAPTER  VII 

BANDED  TRUNKS  AND  WOODS  (Continued) 
Broadleaf  Series,  Part  Two  (Dicotyledons) 

White  wood  Group  (Tulip  Tree,  Poplar,  Cottonwood,  Black  Cotton- 
wood,  Cucumber-tree,  Basswood,  etc.);  Willow  (Black  Willow, 
White  Willow,  etc.);  Catalpa  (Hardy  Catalpa,  Catalpa,  etc.); 
Mulberry  (Red  Mulberry,  etc.);  Horse  Chestnut.  Buckeye 
(Ohio  Buckeye,  Sweet  Buckeye,  etc.);  Gum  (Sweet  Gum,  Tupelo 
Gum,  Sour  Gum);  Holly.  Boxwood.  Lignumvitse  (Holly,  Dog- 
wood, Lignumvitse,  etc.);  Laurel  (California  Laurel,  Madrona, 
etc.);  Sassafras.  Camphor  (Sassafras);  Greenheart  (Greenheart) ; 
Persimmon.  Ebony  (Persimmon) ;  Osage  Orange.  Cherry  (Osage 
Orange,  Wild  Black  Cherry) ;  Mahogany  (Mahogany,  Spanish 
Cedar,  White  Mahogany);  Satinwood;  Teak  (Teak);  Some  Tropical 
Species  (Sabicu,  Sissoo,  Rubber  Tree,  California  Pepper,  China- 
berry,  Rosewood,  Sandalwood) ;  Eucalyptus  (Blue  Gum,  Red  Gum, 
Jarrah,  Karri,  Tuart,  Sugar  Gum,  Giant  Eucalypt,  Manna  Gum, 
Stringybark,  Red  Mahogany,  etc.) 169 

CHAPTER  VIII 

NON-BANDED  TRUNKS  AND  WOODS 
(Monocotyledons) 

General  and  Introductory.  Parts  of  the  Trunk.  Wood-Elements. 
Uses.  Sub-Divisions.  Palm  (Washington  Palm,  Date  Palm, 
Cabbage  Palmetto,  etc.);  Yucca  (Joshua-tree);  Bamboo  (Bamboo, 
etc.) .224 


TABLE  OF  CONTENTS 


CHAPTER  IX 

PAGE 

SPECIAL  PROPERTIES  OF  WOODS  DUE  TO  THEIR  ORGANIC  ORIGIN.    CHEMICAL 

COMPOSITION    OF    WOODS.     PHYSICAL    PROPERTIES    OF    WOODS: 

DESCRIPTIONS   OF   WEIGHTS    AND    MODULI   EMPLOYED. 

MOISTURE  IN  WOODS;  INFLUENCE  OF  MOISTURE, 

ANTISEPTICS,    AND    HEAT    UPON    THE 

PHYSICAL  PROPERTIES  OF  WOODS 

General  and  Introductory.  Special  Properties  due  to  Organic  Origin. 
Chemical  Composition:  Chemical  Elements;  Organic  Compounds 
(Cellulose,  Lignin,  Associated  Materials);  Inorganic  Compounds. 
Physical  Properties:  Descriptions  of  Physical  Properties;  Strength, 
Rigidity,  Elasticity,  Resilience,  Hardness,  Ability  to  Hold  Fasten- 
ings, Weight,  Specific  Gravity  and  Density,  Porosity,  Conduc- 
tivity, Resonance.  Measurements  of  Physical  Properties  (Diffi- 
culties, Selection  and  Preparation  of  Test-Pieces,  Sizes  of  Test- 
Pieces,  Standards  for  Moisture,  Woods  Compared  with  Stones  and 
Metals,  Existing  Experiments  Separated  into  Groups).  Descrip- 
tions of  Weights  and  Moduli  Employed.  Influence  of 'Moisture, 
Antiseptics,  and  Heat  upon  Physical  Properties :  Moisture  in  Wood 
(Quantity  of  Moisture,  Distribution  of  Moisture,  Influence  of 
Moisture  upon  Decay,  Influence  of  Moisture  upon  Physical  Prop- 
erties, Influence  of  Moisture  upon  Distortion).  Influence  of  Anti- 
septics upon  Physical  Properties.  Influence  of  Heat  upon  Physical 
Properties .  .  233 


CHAPTER  X 

FAILURE  OF  WOOD  BECAUSE  OF  USE,  EXPOSURE,  AGE,  AND  DECAY 

General  and  Introductory.  Failure  of  Wood  because  of  Use.  Failure 
of  Wood  because  of  Exposure.  Failure  of  Wood  because  of  Age. 
Fungous  Diseases:  Fungi  (Descriptions,  Conditions  under  which 
Fungi  Act);  Fungous  Diseases  of  Trees  (Diseases  of  Foliage,  Dis- 
eases of  Roots,  Diseases  of  Trunks) ;  Fungous  Diseases  of  Structural 
Woods  (Life  of  Fungi  Influenced  by  Position  or  Exposure  of  Wood, 
First  Exposure,  Second  Exposure,  Third  Exposure,  Influence  of 
Top-Soil,  etc.,  Fourth  Exposure,  Evidence  of  Disease,  Methods  of 
Treatment,  Methods  of  Protection) 267 


TABLE  OF  CONTENTS  xi 

CHAPTER  XI 

•  FAILURE  OF  WOOD  BECAUSE  OF  FIRE.     WOOD  AS  AN  AGENT  IN 
CONFLAGRATIONS.     FIRE  PROTECTION 

PAGE 

General  and  Introductory.  Fire  Losses  in  the  United  States.  Com- 
parison of  Losses  with  those  in  Other  Countries.  A  Principal 
Cause  for  Excessive  Fire  Losses  in  the  United  States.  Wood  as  an 
Agent  in  Conflagrations:  The  Burning  of  Wood;  Attempts  to  Pre- 
vent Wood  from  Burning;  Internal  Protection  (Fire-Retarding 
Materials,  Processes  for  Introducing  Fire-Retarding  Materials 
within  Woods,  Preparation  of  Woods  to  Receive  Fire-Retarding 
Materials) ;  External  Protection  (Materials,  Fireproof  Paints, 
Metals,  etc.,  Methods  used  to  Apply  Materials,  Preparation  of 
Woods  to  Receive  Materials);  Methods  of  Testing  "Protected" 
Woods;  Methods  used  to  Extinguish  Burning  Woods;  Materials 
(Water,  Carbon  Dioxide,  Carbon  Tetrachloride,  etc.);  Devices  for 
Applying  Materials  (Fire  Engines,  Chemical  Engines,  Extin- 
guishers) ;  Organizations.  Some  Principles  of  Fire  Protection :  His- 
torical and  Introductory;  Burning  Buildings  (Inside  Fires,  Outside 
Fires,  Temperatures  in  Burning  Buildings);  Methods  by  which 
Buildings  are  Prevented  from  Burning;  Materials  (Metals,  Natural 
Stones,  Artificial  Stones,  Combinations);  Influence  of  Design, 
Special  Devices,  etc.  (Fireproof  Construction,  Roofs,  Door  Open- 
ings, Fire-Doors,  Window  Openings,  Fire-Shutters,  Wired-Glass, 
Automatic  Sprinklers,  Signals) ;  Care  or  Maintenance  of  Structures 
(Inflammable  Stores,  Watchmen's  Recorders) 277 

CHAPTER  XII 

FAILURE  OF  WOOD  BECAUSE  OF  ANIMAL  LIFE.     MARINE  AND  TER- 
RESTRIAL WOODBORERS.      METHODS   OF   PROTECTION 

Introductory.  Marine  Woodborers:  The  Shipworm;  Form,  Physiology, 
Reproduction,  and  Development,  Influence  of  Temperature  and 
Water,  Method  of  Attack,  Size  of  Borings,  Rapidity  of  Work, 
Field  of  Attack,  Woods  Subject  to  Attack:  The  Limnoria;  Form 
and  Physiology,  Influence  of  Temperature  and  Water,  Method  of 
Attack,  Character  of  Excavation,  Size  of  Borings,  Rapidity  of 
Work,  Field  of  Attack,  Woods  Subject  to  Attack:  The  Chelura; 
Form  and  Physiology,  Method  of  Attack,  Character  of  Excavation, 
Size  of  Borings,  Field  of  Attack :  Miscellaneous ;  Fresh  Water 
Borers,  Stone  Borers,  Barnacles.  Methods  of  Protection:  Removal 
during  the  Breeding  Season;  Change  of  Water;  Use  of  Selected 
Woods;  External  Coatings  (Bark,  Planks,  Metals,  Teredo  Nails, 
Paraffin,  Tar,  Paints,  Reinforced  Coatings,  Cement,  Sand,  Natural 
Protection);  Preservatives  Applied  within  Woods  (Creosotes); 
Substitution.  Terrestrial  Woodborers:  General;  Beetles  (Char- 
acteristics, Summary);  Moths  and  Butterflies  (Characteristics, 
Summary);  Termites  or  White  Ants  (Characteristics,  Protection, 
Summary);  Black  Carpenter  Ant;  Carpenter  Bee.  Methods  of 
Protection . 


xii  TABLE  OF  CONTENTS 

CHAPTER  XIII 

PROTECTIVE  METHODS — SEASONING 

PAGE 

General  and  Introductory.  Natural  Seasoning.  Water  Seasoning. 
Kiln  Seasoning  (General,  Influence  of  Temperature,  Influence  of 
Moisture,  Air-currents,  Forms  of  Kilns,  Operation  of  Kilns,  Diffi- 
culties, Time  Required).  Protection  of  Seasoned  Woods  ....  326 

CHAPTER  XIV 

PROTECTIVE    METHODS — INTERNAL    TREATMENT.     PRESERVA- 
TIVE COMPOUNDS  APPLIED  WITHIN  WOODS 

General  and  Introductory.  Materials:  Tannin;  Copper  Sulphate; 
Mercury  Bichloride;  Zinc  Chloride;  Creosote  (General,  Definitions, 
Specifications,  Analyses,  Required  Quantities,  Distribution,  etc.); 
Miscellaneous  Materials  (Carbolineum).  Processes  Used  to  Intro- 
duce Antiseptics  within  Woods;  Superficial  Processes  (Dipping, 
Soaking,  Brush  Applications);  Non-Pressure  Processes  (The  Kyan 
and  Open-Tank  Processes);  Pressure  Processes  (Use  of  Cylinders, 
Pressure,  Heat  and  Vacuum,  Full  Cell,  Empty  Cell,  Bethell,  Hay- 
ford,  Burnett,  Rutgers,  Card,  Allardyce,  Rueping,  Lowry,  Boiling, 
Wellhouse,  Creo-Resinate,  Creoair,  Boucherie,  Charring,  Vulcan- 
izing, Robbins,  Seeley,  Powell,  Thilmany,  Hasselmann,  and  Ferrell 
Processes) ;  Woods  that  are  to  Receive  Treatment 335 

CHAPTER  XV 

PROTECTIVE    METHODS — EXTERNAL   TREATMENT.     OILS,    PAINTS, 

VARNISHES,  AND  OTHER  COATINGS.     THEIR  APPLICATION  TO 

SURFACES  OF  WOODS 

General  and  Introductory.  Materials:  Oils  (Solidifying  or  Drying  Oils 
and  Driers,  Non-Solidifying  Oils,  Volatile  Oils  and  Spirits);  Pig- 
ments and  Fillers  (White  Lead,  Zinc  White,  Barium  Sulphate,  Red 
Lead,  Iron  Oxides,  Carbon  Paints,  Fillers);  Gums,  Resins,  and 
Varnishes  (Amber,  Copal,  Anime,  Zanzibar,  Kauri,  Shellac,  Sanda- 
rach,  Dammar,  Mastic,  Rosin,  Varnishes);  Miscellaneous  Mate- 
rials (Stains,  Whitewash,  Kalsomine,  Cold  Water  Paints,  etc.). 
Methods  of  Application:  The  Application  of  Paint;  Influence  of 
Application  upon  Durability;  The  Application  of  Varnish  (Plain 
Varnished  Surfaces,  Polished  Surfaces,  Varnish  Paint  or  Enamelled 
Surfaces).  Preparation  of  Woods  to  Receive  Paints  and  Var- 
nishes. Other  Coatings  (Metals,  etc.,  etc.) 377 


TABLE  OF  CONTENTS  xiii 


CHAPTER,  XVI 

ADHESIVES.     CATTLE    GLUES.     FISH    GLUES.     SELECTION,    TESTING  - 
AND  APPLICATION  OF  GLUES 

PAGE 

General  and  Introductory.  Cattle  Glues:  Sources;  Manufacture; 
Properties  (Foreign  and  Domestic  Glues,  Influence  of  Heat  and 
Moisture,  etc.);  Selection;  Application  (Dissolving  the  Glue,  Pre- 
paring the  Wood,  Completing  the  Joint);  Protection  of  Joints 
(Resistance  to  Heat,  Resistance  to  Moisture,  Influence  of  Forma- 
lin); Durability  of  Joints.  Fish  Glues:  Sources;  Manufacture; 
Properties;  Selection;  Application.  Methods  of  Testing  Glues: 
Cattle  Glues  (Standards,  Samples,  Appearance,  Fracture,  Odor, 
Acidity,  Grease,  Viscosity,  Foam,  Strength);  Fish  Glues.  Some 
Uses:  Veneers  (Reasons  for  Preferring  Veneered  Work,  Prepara- 
tion and  Uses  of  Veneered  Work) ...;....,......  403 

CHAPTER  XVII 

INDIARUBBER  AS  A  STRUCTURAL  AND  MACHINE  MATERIAL.     SOURCES, 
PREPARATION,  PROPERTIES,  AND  USES  OF  INDIARUBBER 

General  and  Introductory.  Indiarubber.  Rubber  Latex;  Collection 
of  Latex,  Rubber  obtained  from  Latex.  Geographical  and  Botan- 
ical Classifications  of  Rubber;  Crude  and  Refined  Rubber,  Fresh 
and  Reclaimed  Rubber,  Wild  and  Plantation  Rubber.  Purification 
and  Preparation  of  Rubber.  Vulcanization.  Properties  of  Pure 
Rubber  and  Vulcanized  Rubber.  Synthetic  Rubber.  Uses  of 
Rubber 421 

BIBLIOGRAPHY 437 

INDEX.  .   447 


LIST  OF  PLATES 

FACING 
PLATE  PAGE 

I  Arrangement  of  Wood  Elements — Cross  Sections 18 

II  Arrangement  of  Wood  Elements — Tangential  Sections  ....  22 

III  Arrangement  of  Wood  Elements — Radial  Sections      .....  28 

IV  Influence  of  Wind  upon  Trees  at  Timber  Line     .......  42 

V  Fungous  Diseases  of  Wood 268 

VI  Portion  of  Floor  Beam  after  Attack  by  Dry  Rot  Fungus  .    .    .  274 

VII  Appearance  of  Fire  Doors  after  Fire ;    .  286 

VIII  Details  of  Tin  Clad  Fire  Door.    .  ",    .    .    .    .    .    . 296 

IX  Work  of  the  Shipworm     ...    .    .    .    .    ,    .    .    .    .    .  % 302 

X  Work  of  Shipworm — Large  Borings '  .   ,' 308 

XI  Work  of  the  Limnoria   .    .    .    ...    ............  312 

XII  Work  of  the  Chelura. 314 

XIII  Work  of  Larvae  of  Beetles.      "Bookworms".    ........  318 

XIV  Work  of  Large  Carpenter  Ant.    .    .    .    ."  .....    .    .    ...  322 

XV  High  Power  Spraying  Apparatus  in  Action 324 

XVI  Trough  Employed  in  Kyan  Process 354 

XVII  Open  Tank  Process  Applied  to  Butt  Treatment  of  Poles   .    .    .  358 

XVIII  Steel  Cylinders  Designed  for  Treating  Wood 362 

XIX  Plant  for  Creosoting  Lumber 370 

XX  Application  of  Glue  in  Large  Curved  Joint 416 


xv 


INTRODUCTION 

A  knowledge  of  the  properties  of  the  substances  used  in  con- 
struction gives  confidence  to  those  who  employ  them  and  permits 
smaller  margins  beyond  calculated  requirements  than  otherwise 
would  be  possible. 

Wood  is  one  of  the  primary  materials  of  construction.  The 
others  are  stone  and  iron.  These  fundamental  materials  possess 
distinguishing  properties,  and  each  as  a  class  includes  a  series  of 
individuals  or  varieties,  which  are  again  distinguishable  from  one 
another  by  certain  minor  or  specific  properties. 

All  structural  materials  may  be  divided  as  they  are  organic  and 
inorganic.  Wood  and  other  organic  structural  materials  are 
characterized  by  qualities  due  to  life  processes,  age,  and  other 
physiological  causes.  Stone,  iron,  and  other  inorganic  materials 
are  not  distinguished  in  this  way;  these  materials  are  more 
simple,  homogeneous,  and  constant. 

What  is  now  known  as  "  conservation "  has  been  defined1  as 
"the  greatest  good  to  the  greatest  number — and  that  for  the 
longest  time."  The  idea  of  conservation  includes  the  reduction 
of  waste.  The  future  as  well  as  the  present  is  regarded.  The 
broader  needs  of  the  nation  are  placed  before  the  immediate 
needs  of  the  individual;  and,  whenever  possible,  resources  are 
considered  more  as  they  produce  yearly  incomes  and  less  as 
though  they  were  fixed  sums  to  be  drawn  upon  directly  and  thus 
exhausted  ultimately. 

Woods  and  other  organic  materials  respond  more  completely 
than  metals  and  stones  to  the  application  of  the  principles  of  con- 
servation because  they  can  be  reproduced.  The  development  of 
a  forest  requires  time,  but  such  development  is  possible,  and  once 
established  the  forest  can  be  maintained  so  as  to  yield  for  in" 
definite  periods.  On  the  other  hand,  inorganic  materials  exist 
in  fixed  and  final  quantities.  The  more  the  materials  of  the 

1  Van  Hise  in  "The  Conservation  of  Natural  Resources  in  the  United 
States."  See  also  "The  Fight  for  Conservation,"  Pinchot;  "Conservation 
of  Water  by  Storage,"  Swain  (Yale  University  Press);  etc.,  etc. 

xvii 


xviii  INTRODUCTION 

inorganic  group  are  used,  the  more  quickly  they  will  become 
exhausted,  and  once  exhausted  these  materials  cannot  be 
reproduced. 

Wood  is  the  principal  organic  structural  material  but  it  is  not 
the  only  one.  The  oils  that  are  used  in  paints,  varnish-resins, 
glues,  indiarubber  and  other  materials  are  of  this  series. 


WOOD 

AND  OTHER 

ORGANIC  STRUCTURAL 
MATERIALS 


CHAPTER  I 

WOODS  COMPARED  WITH  STONES  AND  METALS.     COMMON  AND 
BOTANICAL  NAMES.     FUNDAMENTAL  CLASSIFICATIONS 

Information  relating  to  the  general  properties  of  wood  compares 
in  importance  with  information  relating  to  the  general  properties 
of  steel,  stone,  and  cement.  Engineers  use  more  wood  than  any 
other  set  of  men,  yet  general  facts  about  wood,  aside  from  those 
relating  to  its  strength,  are  often  relegated  to  the  consideration 
of  the  botanist  or  the  forester. 

The  consumption  of  wood  has  never  decreased,  although  metals 
and  stones  have  been  substituted  for  it  in  many  positions.  In 
England,  the  consumption  per  capita  more  than  doubled  in  the 
fifty  years  preceding  1895,  in  spite  of  the  fact  that  nearly  all  of 
the  wood  used  in  that  country  had  to  be  imported.  In  1905, 
the  total  yearly  mill  value  of  wood  products  in  the  United  States 
was  over  nine  times  as  great  as  the  combined  product  of  gold  and 
silver,  and  twice  as  great  as  the  value  of  the  wheat  crops.1 

The  importance  of  wood  as  a  material  of  construction  is  well 
expressed  in  the  quotation  that  follows  :2 

"Wood  is  an  indispensable  part  of  the  material  structure  upon  which 
civilization  rests;  and  it  is  to  be  remembered  always  that  the  immense 
increase  of  the  use  of  iron  and  substitutes  for  wood  in  many  structures, 

1  A  conservative  estimate  places  the  yearly  mill  value  of  wood  products 
in  the  United  States  alone  at  $1, 100,000.000.     The  spring  and  winter  wheat 
crops  of  1905  were  together  valued  at  $518,372,727.     The  production  of 
gold  and  silver  during  the  year  1904  was  valued  at  $112,871,026.     See  also 
"Forest   Resources   of   the   World,"    Zon    (United   States   Forest   Service 
Bulletin,  No.  83). 

2  Credited  to  the  Honorable  Theodore  Roosevelt. 

1 


2  ORGANIC  STRUCTURAL  MATERIALS 

while  it  has  meant  a  relative  decrease  in  the  amount  of  wood  used,  has 
been  accompanied  by  an  absolute  increase  in  the  amount  of  wood  used. 
More  wood  is  used  than  ever  before  in  our  history." 

Wood  is  preferred  because  it  is  easily  worked  and  light  in 
weight.  In  many  positions,  it  is  as  durable  as  iron.  When  dry 
it  is  a  poor  conductor  of  heat  and  electricity  and  is  stronger  than 
is  commonly  supposed.  The  tensile  strength  of  a  bar  of  hickory 
may  exceed  the  tensile  strength  of  a  similar  bar  of  wrought  iron 
of  the  same  length  and  weight.1  However,  wood  is  not  homo- 
geneous like  metal  and  most  of  the  stones  that  are  used  for  build- 
ing, but  is  so  variable  that  several  parts  of  the  same  tree  often 
exhibit  widely  different  qualities. 

Most  wood  is  used  in  construction;  that  is,  in  mines,  railways, 
houses,  and  ships  where  size  or  quantity  is  required  and  where 
finish  and  appearance  are  less  important.  Much  wood  is  used  in 
cabinet  work  and  in  positions  where  appearance,  appropriateness, 
and  finish  are  important.  Such  woods  are  more  in  evidence,  but 
the  amounts  used  are  actually  very  much  smaller  than  the  amounts 
used  in  construction.  Some  wood  is  required  for  turnery,  carv- 
ings, and  implements  that  demand  exact  qualities  that  can  be 
secured  in  small  pieces  only.  Some  wood  is  used  indirectly,  and 
in  the  manufacture  of  paper-pulp,  gunpowder,  and  chemicals. 
There  are  also  by-products  of  trees,  such  as  tanbark,  turpentine, 
resin,  and  sugar. 

Common  and  Botanical  Names. — Woods  appear  to  be  more 
numerous  than  they  actually  are,  because  more  than  one  name  is 
so  often  applied  to  the  same  species.  Supplies  are  often  brought 
from  far  distant  places  when  woods  of  the  same  kind  are  available 
nearby,  but  are  not  recognized  because  they  are  called  by  differ- 
ent names.  One  species,  the  Southern,  Yellow,  Georgia,  or 
Longleaf  Pine  (Pinus  palustris),  has  nearly  thirty  local  names. 
Such  confusion  can  be  avoided  only  by  regarding  the  recognized 
botanical  nomenclature. 

Not  only  is  it  true  that  several  names  are  often  applied  to  the 
same  wood,  but,  strange  as  it  may  seem,  a  fairly  constant  single 
product  is  sometimes  derived  from  several  unrelated  species. 
The  single  name  cedar  is  thus  applied  to  several  species  of  durable 
characteristically  scented  woods,  which  have  similar  anatomical 
features  and  which  are  derived  from  species  that  are  not  closely 
related  to  one  another. 

1  United  States  Department  of  Agriculture,  Yearbook,  1896,  p.  392,  Roth. 


NOMENCLA  TURE—CLASSIFICA  TIONS  3 

The  botanical  name  of  a  plant  is  made  up  of  terms  denoting 
genus  and  species.  For  example,  Quercus  is  the  generic  name 
that  includes  all  the  species  of  oak,  while  alba  and  rubra  are 
specific  names  that  apply  to  two  particular  species  of  the  genus 
Oak.  Quercus  alba  and  Quercus  rubra  are  completed  names. 
The  names  of  species  are  not  fixed,  but  differ  with  authorities 
so  that  it  is  often  best  to  add  the  abbreviated  name  of  the 
botanist  responsible  for  the  name  employed.  Illustrations 
would  be  Quercus  alba  Linn.,  Quercus  rubra  Linn.,  and  Ulmus 
fulva  Michx. 

A  genus  may  be  defined  as  a  collection  of  related  species,  and  a 
species  may  be  regarded  as  a  collection  of  individuals  that  might 
easily  have  sprung  from  some  single  stem.  Genera  are  grouped 
into  families,  and  both  genera  and  families  differ  with  authorities. 
The  term  " variety"  is  applied  to  individuals  that  differ  less  from 
one  another  than  do  species.  Quercus  robur  var.  pedunculata 
indicates  a  variety  (var.  pedunculata)  of  a  certain  species  (robur) 
of  Oak  (Quercus).  It  should  be  noted  that  the  variety  of  one 
botanical  authority  is  sometimes  regarded  as  a  distinct  species 
by  another  botanical  authority. 

About  five  hundred  species  of  trees  grow  in  the  United  States1 
and  many  other  species  grow  in  other  countries,  yet,  the  great 
mass  of  wood  that  is  used  in  construction  comes  from  compara- 
tively few  of  these  species.  Sudworth  excludes  all  but  one 
hundred  sources  in  his  "Trees  of  the  United  States  Important 
to  Forestry,"  while  a  United  States  Treasury  Department  Sum- 
mary contains  the  statement  that  but  sixteen  (16)  kinds  of  hard- 
wood were  quoted  in  the  Chicago  markets  on  the  first  day  of 
September  of  the  year  1900.2 

The  statement  is  also  made  in  the  source  referred  to,  that  the  prin- 
cipal timbers  of  commerce  in  the  United  States  are  the  genera  known 
popularly  as  pine,  fir,  oak,  hickory,  hemlock,  ash,  poplar,  maple,  cypress, 
spruce,  cedar  and  walnut. 

Conditions  are  changing.  The  original  forests  are  much  smaller 
than  in  former  years.  Many  woods  that  were  once  common  are 
now  scarce,  while  other  woods  that  were  once  unfamiliar  are 
now  employed. 

1  Fernow  credits  four  hundred  and  ninety-five  species  to  the  United 
States  (Introduction  to  United  States  Forestry  Bulletin  No.  17);  Sargent, 
counting  species  only  and  excluding  varieties,  notes  four  hundred  and 
twenty-two  species  (Silva  of  North  America). 

2 1900,  p.  1081. 


4  ORGANIC  STRUCTURAL  MATERIALS 

Botanical  Classification  of  Trees  and  Their  Woods. — Botanists 
group  trees  as  they  do  other  seed-bearing  plants,  mainly  upon 
the  characteristics  of  parts  other  than  the  trunks.  In  such  groups, 
the  flowers,  fruit,  and  leaves  are  fundamentally  important.  A 
general  classification  is  as  follows : 

I.  GYMNOSPERMS. — The  seeds  are  naked,  that  is,  they  are  not  enclosed 
in  fruit.     There  are  three  natural  groups  or  families  as  follows: 

(a)  Cycadacece. — Practically  confined  to  tropical  and  sub-tropical 
regions.  Practically  valueless  for  wood.  To  be  here  disregarded. 

(&)  Gnetacece. — Consists  of  undershrubs,  shrubs,  and  small  trees,  most 
of  which  grow  in  the  tropics.  Practically  valueless  for  wood.  To  be 
here  disregarded. 

(c)  Coniferce. — This  is  by  far  the  largest  and  most  important  of  the 
three  families,  and  the  only  one  that  yields  merchantable  lumber.  The 
Pines,  Spruces,  Firs,  and  Cedars  are  among  the  members  of  this  family. 
The  seeds  are  borne  on  series  of  overlapping  scales,  arranged  in  what 
are  known  as  cones.  The  leaves  of  ordinary  species  are  narrow,  rigid, 
needle-like,  or  scale-like.  Resins  are  present.  The  trees  are  sometimes 
called  Needle-leaf,  Softwood,  and  Evergreen  trees,  as  well  as  Coniferous 
and  Cone-bearing  trees. 

II.  ANGIOSPERMS. — The  seeds  are  always  enclosed  in  more  or  less  obvi- 
ous seed-vessels  or  fruit.     These  plants  greatly  exceed  those  in  the  pre- 
ceding groups  in  the  number  of  their  species  and  in  the  variety  of  their 
habits.     All  ordinary  flowering  plants  are  Angiosperms.     There  are  two 
classes,  which,  while  they  agree  in  having  enclosed  seeds,  differ  in  other 
matters,  and  in  none  more  than  in  the  structure  of  their  stems  or  trunks. 
The  Angiosperms  are  sub-divided  as  follows: 

(a)  Monocotyledons. — These  plants  have  one  seed  leaf  or  cotyledon, 
whence  the  name,  Mono-cotyledon.  The  veins  in  the  leaves  are  more 
or  less  parallel  to  one  another.  Some  twenty-five  thousand  species  are 
recognized,  but  very  few  of  these  species  yield  woods  that  are  valued 
in  construction.  The  few  Monocotyledons  that  yield  woods  that  are 
valued  in  construction  are  associated  with  the  tropics.  The  Palms  and 
Bamboos  are  Monocotyledons. 

(6)  Dicotyledons. — These  plants  have  two  seed-leaves  or  cotyledons, 
whence  the  name  ZH-cotyledon .  The  veins  in  the  leaves  of  the  Dicotyle- 
dons are  netted.  The  stems  of  these  plants  increase  by  layers  of  new 
material  that  form,  each  one  upon  the  outside  of  others  that  were  formed 
before.  Coniferous  trees  increase  in  practically  the  same  manner.  Sev- 
eral hundreds  of  the  over  one  hundred  thousand  Dicotyledons  are  trees, 
and  these  Dicotyledonous  trees  yield  the  so-called  Broadleaf  woods, 
Deciduous  woods,  or  Hardwoods  of  commerce.  The  Oaks,  Maples,  and 
Hickories  are  among  the  Dicotyledons. 


NOMENCLA  TURE—CLASSIF1 CA  TIONS  5 

The  woods  that  are  valued  in  construction  are  derived  from  the 
Conifers,  the  Dicotyledons,  and  the  Monocotyledons,  in  the  order 
named.  The  other  divisions  of  plant  life  do  not  produce  mer- 
chantable woods  and  may  be  disregarded  in  this  connection. 

Practical  Classification  of  Trees  and  Their  Woods. — Those 
who  use  woods  are  less  concerned  with  the  flowers,  fruit,  and 
leaves  of  the  trees,  than  with  the  trunks,  and  the  charac- 
teristics of  the  woods  themselves.  The  present  text  has  for  its 
object  a  study  of  woods,  as  distinct  from  trees,  and  for  this 
reason,  the  features  of  flowers,  fruit,  and  leaves,  which  are  so 
important  to  the  botanist,  will  be  regarded  as  secondary,  and 
woods  will  be  classified  upon  the  basis  of  their  own  properties. 

From  this  viewpoint  all  trees,  trunks,  and  woods  will  be  divided 
primarily  according  to  the  way  in  which  new  material  is  added  to 
their  sections.  Two  great  divisions  will  be  distinguished: 

1.  Banded  Trunks  and  Woods. — In  this  case  the  wood  is 
arranged  in  concentric  bands  or  layers  which,  in  cross-sections, 
appear  as  rings.  The  trees  that  yield  banded  woods  are  all 


FIG.  1. — Section  through  a  banded  trunk  (longleaf  pine,  Pinus  paliLstris}. 

"outside-growers;"  that  is,  new  material  is  deposited  in  layers, 
each  one  of  which  is  formed  upon  the  outside  of  other  layers  that 
were  formed  before.  Pines,  oaks,  and  practically  all  other  trees 
that  yield  woods  that  are  valued  in  construction  are  included  in 
this  division.  It  is  the  group  to  which  the  name  Exogen,  or 
Outside-grower,  has  been  applied  by  the  engineer. 


6 


ORGANIC  STRUCTURAL  MATERIALS 


The  names  Exogen  and  Endogen  are  undesirable  because  engineers  and 
botanists  seldom  employ  them  in  the  same  way.  Some  botanists  use  the 
name  Endogen  in  connection  with  Monocotyledonous  trees  and  woods,  but 
restrict  the  use  of  Exogen  to  Dicotyledonous  trees  and  woods,  while  others 
do  not  employ  these  terms  at  all. 

This  group  is  divided  into  Conifers  and  Dicotyledons.  The 
first  sub-series  includes  the  so-called  Softwoods.  Coniferous, 
Softwood,  Needleleaf  and  Evergreen  woods  are  the  same.  It 
should  be  noted  that  in  spite  of  the  use  of  the  word  Softwood 
some  of  the  individuals  of  this  sub-series  are  actually  very  hard. 
The  Dicotyledons  are  often  referred  to  as  Hardwoods  although 
some  of  them  are  really  quite  soft.  Dicotyledonous,  Hardwood, 
Non-coniferous,  and  Deciduous  woods  are  the  same. 

2.  Non-banded  Trunks  and  Woods. — These  woods  are  not 
arranged  in  concentric  rings  or  layers.  On  the  contrary,  the 


FIG.  2. — Section  through  a  non-banded  trunk  (royal  palm,  Oreodoxa  regid). 


NOMENCLA  T  URE—CLASSIFICA  TIONS  7 

wood  is  scattered  irregularly  in  small  fibrous  groups  throughout 
the  tree  which  is,  therefore,  known  as  an  " inside-grower." 

The  Palms,  Bamboos,  and  a  few  other  plants  of  this  group 
that  yield  useful  woods  are  associated  with  the  tropics.  The 
woods  are  seldom  used  much  in  construction  far  from  the  places 
in  which  they  grow.  This  group  includes  the  Monocotyledons 
of  the  botanist  and  is  the  one  to  which  the  name  Endogen,  or 
Inside-grower,  has  been  applied  by  engineers.1 


1  See  first  paragraph  page  6. 


CHAPTER  II 


TREES.     PHYSIOLOGY    OF    TREES.     VALUE    OF    FORESTS. 

FORESTRY 

A  study  of  iron  begins  at  the  furnace;  a  knowledge  of  stone 
must  include  some  facts  with  regard  to  the  quarry  from  which  the 
stone  was  taken;  in  the  same  way  a  study  of  wood  must  commence 

with  a  study  of  the  tree  within  which 
the  wood  was  formed. 

PHYSIOLOGY  OF  TREES.— A  tree 
has  been  defined  (Century  Dictionary) 
as  "a  perennial  plant  which  grows 
from  the  ground  with  a  single,  perma- 
nent, woody,  self-supporting  trunk  or 
stem,  ordinarily  attaining  a  height  of 
at  least  twenty  or  thirty  feet."  A 
tree  has  three  principal  parts  or  sys- 
tems; they  are  the  roots,  the  leaves  or 
foliage,  and  the  stem  or  trunk.  The 
roots  and  the  foliage  are  here  regarded 
only  as  they  are  means  by  which  the 
wood  of  the  stem  is  manufactured. 

The  Roots. — This  system  of  branches 
is  as  extensive  as  the  one  at  the  top 
of  the  tree.  Roots  serve  in  two  ways: 
(1)  they  give  stability  and  hold  the 
tree  firmly  in  its  place;  (2)  they  absorb 
moisture  and  various  nutrient  salts 
from  the  soil.  With  the  exception  of 
carbon  and  some  oxygen  used  in 
respiration,  all  of  the  elements  needed 
for  the  growth  of  trees  are  obtained  from  the  soil  through  their 
roots. 

REFERENCES. — " Cyclopedia  of  American  Horticulture,"  Bailey;  "Fores- 
try for  Farmers,"  Fernow  (United  States  Division  of  Forestry  Bulletin  No. 
10);  "First  Book  of  Forestry,"  Roth;  "Outlines  of  Botany,"  Leavitt 
(American  Book  Company);  "Plant  Anatomy,"  Stevens  (Second  Edition). 

8 


FIG.  3. — Roots,  a,  Cross- 
section  through  root;  6, 
hairroots  enlarged. 


PHYSIOLOGY  OF  TREES— FORESTRY 


I— One  year 
J     old 


The  Leaves. — Carbon,  in  the  form  of  carbon  dioxide,  is  ob- 
tained from  the  atmosphere  by  means  of  the  green  coloring  matter 
which  forms  part  of  the  leaf  and  which  is  known  as  chlorophyll. 
Leaves  also  serve  as  laboratories  within  which  food  materials 
are  formed  which  may  finally  enter  into  the  formation  of  wood. 

By  some  peculiar  property  of  the  chlorophyll,  the  living  tissue 
of  the  leaf  is  able,  in  the  presence  of  sunlight,  to  split  apart  the 
C02  and  to  recombine  the  constituents  with  H20  so  as  to  form  a 
carbohydrate,  probably  some  form  of  sugar. 1 
The  chemical  formulas  of  grape  sugar 
(C6H12O6)  and  cellulose  (C6H10O5)  are 
essentially  alike,  so  it  is  clear  that,  with  the 
development  of  carbohydrate  compounds 
in  the  leaves,  a  fundamental  step  has  been 
taken  toward  the  formation  of  wood. 

The  Trunk. — The  trunks  of  trees  that 
yield  banded  woods  must  be  distinguished 
from  the  trunks  of  trees  that  yield  non- 
banded  woods.  In  the  first  group,  the 
wood-elements  are  arranged  in  concentric 
bands  or  layers,  while  in  the  second  group 
they  are  distributed  in  separate  bundles  so 
that  the  cross  sections,  in  this  case,  appear 
as  though  dotted  (Figs.  1  and  2). 

All  trunks  increase  in  two  ways :  in  length 
and  in  thickness.  Increase  in  length  is 
quite  distinct  from  increase  in  thickness. 
The  terms  length-growth  and  thickness- 
growth  will  be  employed  to  indicate  these 
two  methods  of  increase. 

Length-growth. — All  trees  lengthen  by 
means  of  material  that  forms  upon  the 
ends  of  the  main  axis  and  of  the  twigs 
and  branches.  A  point  of  embryonic  cells 
exists  at  the  end  of  each  ultimate  twig. 
These  apical  cells  grow,  divide,  and  in  the  course  of  the  year 
leave  behind  them  a  whole  new  section  of  twig  with  its  leaves. 
The  twig  then  thickens  by  a  centrifugal  growth  to  be  described, 
and  eventually  the  twig  becomes  a  part  of  the  bough. 

1  "Light  in  Relation  to  Tree  Growth,"  Zon  and  Graves  (United  States 
Forest  Service,  Bulletin  No.  92.) 


.Hwo  years 

old 


10  ORGANIC  STRUCTURAL  MATERIALS 

Length-growth  precedes  thickness-growth  and  is  quite  distinct 
from  it.  A  nail  driven  into  a  tree  at  a  certain  distance  up  from 
the  ground  may  be  finally  covered  by  new  wood  material,  but  it 
will  not  move  up  higher  from  the  ground. 

Thickness- growth. — With  several  exceptions,  the  few  trees 
that  yield  non-banded  woods  do  not  increase  in  diameter  by  the 
formation  of  new  layers  deposited  upon  the  outside  of  older 
growth.  On  the  contrary  these  trees  increase  largely  by  the 
expansion  of  cells  already  formed.  The  trunks  of  these  trees, 
few  of  which  are  of  structural  importance,  do  not  continue  to 
increase  in  diameter  throughout  their  lives,  but  normally  attain 
maximum  diameters  comparatively  early  in  their  growth. 

The  trees  that  yield  banded  woods  thicken  as  follows: 

During  the  first  year,  the  wood  material  is  in  separate 
bundles  arranged  in  a  circle,  but  later  these  bundles  are  fused 
together  so  as  to  form  a  more  or  less  compact  cylinder.  The 


a  6  c 

FIG.  5. — Cross-section  of  very  young  banded  stem,  a,  Six  fibro-vas- 
cular  bundles  are  shown,  b,  The  same  stem  later;  the  bundles  are  increased 
to  twelve,  c,  At  the  end  of  the  year  the  bundles  are  in  the  form  of  wedges 
separated  by  pith  rays.  Acknowledgments  to  "Outlines  of  Botany," 
Leavitt  (American  Book  Company). 

tissue  known  as  primary  wood  is  included  in  this  early  growth.1 
The  several  stages  during  the  first  year  are  sufficiently  indicated 
in  the  pictures. 

After  the  first  year,  the  food  materials,  which  are  formed  in 
the  leaves,  descend  to  the  growing  part  where  the  new  wood 
is  formed.  This  part  is  known  as  the  "  cambium  layer."  Wood 
formed  from  the  cambium  layer  is  known  as  secondary  wood. 
Practically  all  of  the  wood  formed  by  the  tree  is  of  this  kind. 
After  the  first  year  a  new  layer  of  secondary  wood  is  formed 
every  growing  season,  and  these  annual  layers  or  bands  are 
characteristic  of  all  banded  woods. 

1  Tissue  at  the  growing  end  of  the  twig  forms  primary  wood.  The  thin- 
walled  cells  of  which  it  is  composed  are  essentially  similar  to  one  another. 


PHYSIOLOGY  OF  TREES— FORESTRY  11 

The  Cambium  Layer. — This  part,  which  is  of  fundamental 
importance  to  the  life  of  the  tree,  occupies  the  region  between  the 
sapwood  and  the  bark,  and  may  be  described  as  a  thin-walled 
formative  tissue  within  which,  by  cell-division,  growth,  and 
modification,  all  wood-elements  originate.  The  cambium  layer 
consists  of  essentially  the  same  kind  of  embryonic  cells  as  those 
at  the  tips  of  the  twigs. 

The  cambium  layer,  which  suggests  a  thin  layer  of  mucilage,  is  com- 
posed of  very  thin-walled  cells,  filled  with  protoplasm,  and  other  organic 
and  nutrient  compounds.  These  cells  multiply  and  develop.  The  inner 
cells  eventually  form  a  new  layer  of  wood  while  those  at  the  outside  form 
bark.  The  wood  cells,  which  are  at  first  soft  and  delicate,  become 
harder,  as  a  material  known  as  lignin  begins  to  be  deposited  within  their 
walls.  The  resulting  change  from  the  soft  cell  to  the  tough,  woody  cell 
is  known  as  lignification. 

The  cambium,  in  its  centrifugal  advance,  may  leave  one  hun- 
dred or  more  thin  layers  of  wood-elements  behind  every  year  and 
these  very  thin  deposits  together  make  up  what  is  commonly 
known  as  the  " annual  band"  already  mentioned. 

Sap  Movement. — In  the  trees  that  yield  banded  woods,  the 
"  crude  sap,"  containing  mineral  nutrients  drawn  from  the  soil, 
leaves  the  roots  and  passes  upward  through  the  outer  sapwood  to 
the  foliage  where  the  sap  is  by  complex  chemical  changes  "  elabor- 
ated." The  elaborated  or  completed  sap,  containing  the  more 
complex  organic  preparations  needed  for  the  life  of  the  tree,  then 
descends  through  the  inner  bark  to  the  growing  parts. 

The  fluids  of  a  tree  move  continuously  during  the  growing 
season.  Up-currents  and  down-currents  move  simultaneously. 
In  the  main,  fluids  pass  upward  through  the  outer  sapwood  and 
downward  through  the  inner  bark,  as  has  been  noted.  This 
continues  through  the  larger  part  of  the  year  and  is  not  confined 
to  the  spring  alone  as  some  suppose. 

The  means  by  which  sap  ascends  to  the  top  of  the  tree  are  not 
fully  understood,  but  evidence  exists  that  the  force  is  not  capillary 
to  the  extent  that  was  formerly  supposed.  The  passage  upward 
is  doubtless  encouraged  by  the  evaporation  of  water  from  the 
leaves,  but  how  far  this  acts  in  raising  the  water  through  dis- 
tances as  great  as  several  hundred  feet  is  not  known.1 

iSee  "Tracheids." 


12 


ORGANIC  STRUCTURAL  MATERIALS 


Influence  of  Sunlight. — All  trees  require  sunlight  and  are 
influenced  by  the  way  in  which  they  receive  it.  A  tree  that 
stands  by  itself  in  the  open  will  differ  in  form  from  a  tree  that 
stands  with  others  in  the  forest.  In  the  former  environment,  the 
growth  of  lower  branches  is  encouraged,  while  in  the  latter 
environment,  it  may  be  discouraged.  Sunlight  does  not  have 
free  access  to  the  side  branches  of  ordinary  trees  standing  near 
together  in  a  forest.  The  higher  branches  of  such  trees  are  there- 
fore better  nourished.  These  extend  upward  toward  the  sun- 
light, and  consequently  longer,  cleaner  trunks  are  formed. 


FIG.  6. — Sugar  maple  tree  grown  in  the  open.     (By  courtesy  of  American 
Museum  of  Natural  History.) 

It  is  possible  to  modify  the  shapes  of  trees.  Either  full- 
branched  trees,  that  are  prized  in  landscape  effects,  or  long, 
straight  trunks  that  are  valued  by  lumbermen  can  be  obtained 
by  proper  exposure  to  sunlight.  The  lower  branches  of  many 
forest  trees  are  pruned  away  by  nature,  that  is,  these  branches 
die  naturally  for  want  of  sunlight.  In  other  cases  the  same 
results  are  obtained  by  ordinary  pruning.  In  any  case  where 
lower  branches  are  removed,  wood-making  material  which  would 
otherwise  pass  into  these  branches  is  diverted  to  the  trunk. 

The  value  and  influence  of  sunlight  are  described  in  the  follow- 
ing quotation:1 

1  " Light  in  Relation  to  Tree  Growth,"  Zon  and  Graves  (United  States 
Forest  Service  Bulletin  No.  92). 


PHYSIOLOGY  OF  TREES— FORESTRY 


13 


"Light  is  indispensable  for  the  life  and  growth  of  trees.     In  common 
with  other  green  plants  a  tree,  in  order  to  live,  must  produce  organic 
substance  for  the  building  of  new  tissues.     Certain  low  forms  of  vege- 
table life,  such  as  bacteria  and  fungi,  do  not 
require  light.     They  exist  by  absorbing  organic 
substance   from  other  living  bodies;    but  the 
higher  forms  of  plants  manufacture  their  own 
organic  material  by  extracting  carbon  from  the 
air.      The  leaves,  through  the  agency  of  their 
chlorophyll,   or   green  coloring-matter,   absorb 
from  the  air  carbon  dioxide,   and   give  off  a 
nearly  equal  volume  of  oxygen.     The  carbon 
dioxide  is  then  broken  up  into  its  elements  and 
converted   into   organic   substances  which  are 
used  in  building  up  new  tissues. 

"Light  is  not  only  indispensable  for  photo- 
synthesis, but  it  is  essential  for  the  formation 
of  chlorophyll.  Only  in  exceptional  cases,  as  in 
the  embryo  of  fir,  pine,  and  cedar  seeds,  does 
chlorophyll  form  in  the  dark,  and,  with  the 
exception  of  some  microbes,  the  green  cell  is 
the  only  place  where  organic  material  is  built 
up  from  inorganic  substances. 

"Light  also  influences  transpiration,  and 
consequently  the  metabolism  of  green  plants. 
It  influences  largely  the  structure,  the  form, 
and  the  color  of  the  leaf,  and  the  form  of  the 
stem  and  the  crown  of  the  tree.  In  the  forest 
it  largely  determines  the  height-growth  of 
trees,  the  rate  at  which  stands  thin  out  with 
age,  the  progress  of  natural  pruning,  the 
character  of  the  living  ground  cover,  the  vigor 
of  young  tree  growth,  the  existence  of  several- 
storied  forests,  and  many  other  phenomena 
upon  which  the  management  of  forests  depends. 
A  thorough  understanding,  therefore,  of  the  effect  of  light  upon  the  life 
of  individual  trees,  and  especially  on  trees  in  the  forest,  and  a  knowledge 
of  the  methods  by  which  the  extent  of  this  effect  can  be  determined 
are  essential  for  successful  cultural  operations  in  the  forest." 

VALUE  OF  FORESTS. — The  top-  soil  of  forests  is  porous  and 
loose.  The  mixture  of  leaves  and  loose  top-soil  that  forms  under 
the  trees  is  known  as  " humus."  The  humus  receives  and  pro- 
tects young  seeds  and  is  also  valuable  because  it  assists  in  equal- 
izing the  flow  of  streams. 


FIG.  7. — Tulip  tree 
grown  in  the  forest. 
(Courtesy  of  the 
American  Museum 
of  Natural  History.) 


14 


ORGANIC  STRUCTURAL  MATERIALS 


Rain-water  rolls  quickly  from  sun-baked  or  otherwise  com- 
pacted soil,  but  humus  permits  the  raindrops  to  pass  through 
into  the  more  or  less  broken  and  comparatively  loose  and  porous 
soil  below  and  then  obstructs  the  free  evaporation  of  moisture 
from  this  soil.  It  is  not  known  that  forests  influence  rainfall, 
but  their  value  in  regulating  stream-flow  is  beyond  estimate.1 


FIG.  8. — Ability  of  Surface  Materials  to  hold  Water.  A,  Most  of  the  water 
in  this  bottle,  which  contains  gravel,  has  passed  through  into  the  beaker. 
B,  C,  and  D,  These  bottles  contain  sand,  barren  soil  and  loam.  E,  This 
contains  leaf  mould,  which  retains  the  most  water.  F,  This  contains  leaves. 
(From  "Trees  and  Forestry,"  Dickerson.  By  permission  American  Museum 
of  Natural  History.) 

Forests  Reduce  or  Prevent  Erosion. — The  humus  protects  the 
surface,  and  the  roots  contribute  to  the  resistance  offered  by  the 
soil  below.  Water  flows  with  erosive  force  over  unprotected 
and  hardened  surfaces.  Quantities  of  soil  are  carried  from 
higher  elevations  and  deposited  on  lands  below.  Such  results 
may  be  far  reaching.  Districts  such  as  parts  of  India,  China, 
Palestine,  and  Spain,  that  have  supported  considerable  popula- 
tions in  the  past,  have  been  changed  in  this  way  and  are  now 
little  else  than  deserts. 

xLeighton  estimated  that  the  flood  damages  to  this  country  amounted 
to  $237,800,000  in  1908;  "Conservation  of  Natural  Resources  in  the  United 
States"  (Van  Hise,  p.  182).  See  also  Swain  in  "American  Forestry," 
April,  1910,  and  Burr  in  "Engineering  News,"  July  27,  1911,  etc. 


PHYSIOLOGY  OF  TREES— FORESTRY  15 

The  possibilities  in  this  direction  are  described  further  as 
follows  (Van  Hise1) : 

"Not  only  so,  but  after  the  rivers  are  partly  filled  with  silt,  at  times 
of  flood  they  overflow  their  banks  and  often  cover  with  coarse  debris 
large  areas  of  arable  land.  When  this  process  of  erosion  has  continued 
for  a  sufficient  length  of  time  after  the  removal  of  the  forests,  the  steep 
mountains  are  left  with  nearly  bare  rock  and  little  soil.  When  this 
stage  of  the  process  has  been  reached  the  violence  of  the  floods  is  then 
further  greatly  increased.  The  rain  falling  upon  the  bare  rocks  is  car- 
ried down  to  the  streams  below  as  from  the  roof  of  a  house,  and  unites 
in  torrential  floods.  It  is  after  this  condition  of  affairs  has  come  about 
as  a  result  of  a  removal  of  the  forests  that  the  enormous  flood  losses 
occur  to  railroads,  cities,  and  other  structures  of  man." 

FORESTRY. — Forestry  is  a  phase  of  agriculture,  rather  than 
of  lumbering.  Under  this  system  forests  are  not  destroyed  for 
immediate  profit  but  are  maintained  so  as  to  secure  recurring 
crops  of  desirable,  matured  trees.  Besides  this,  appropriate 
species  are  planted,  top-soil  or  humus  is  preserved,  fire  risks  are 
lowered,  and  young  trees  are  introduced  as  older  ones  are  cut 
down.  Forestry  yields  smaller  profits  but  these  continue  from 
year  to  year.  The  lumberman,  who  disregards  the  principles 
of  forestry,  receives  larger  profits  once  and  for  all. 

The  results  that  may  be  obtained  by  the  practice  of  forestry 
are  expressed  in  the  quotations  that  follow  :2 

"Under  right  management  our  forests  will  yield  over  four  times  as 
much  as  now.  We  can  reduce  waste  in  the  woods  and  in  the  mill  at 
least  one-third,  with  present  as  well  as  future  profit.  We  can  perpetuate 
the  naval-stores  industry.  Preservative  treatment  will  reduce  by  one- 
fifth  the  quantity  of  timber  used  in  the  water  or  in  the  ground.  We 
can  practically  stop  forest  fires  at  a  total  yearly  cost  of  one-fifth  the 
value  of  the  standing  timber  burned  each  year."  ....  "By  reason- 
able thrift  we  can  produce  a  constant  timber  supply  beyond  our  present 
need  and  with  it  conserve  the  usefulness  of  our  streams  for  irrigation, 
water-supply,  navigation,  and  power." 

1  "Conservation  of  Natural  Resources  in  United  States"  (p.  246).     See 
also  "Washed  Soils  and  How  to  Prevent  Them"   (United  States  Dept. 
Agriculture,  Farmers'  Bulletin  No.  20);   "Conservation  of  Water  by  Stor- 
age," Swain  (Yale  University  Press,  1915). 

2  United  States  Forest  Service  Circular  No.  171,  Price,  Kellogg  and  Cox. 


16  ORGANIC  STRUCTURAL  MATERIALS 

The  size  and  character  of  the  trunk,  and  the  range,  locality, 
and  distribution  of  the  species,  have  much  to  do  with  the  utility 
of  the  wood.  Large  and  perfect  timbers  cannot  be  derived  from 
species  characterized  by  small  or  crooked  trees.  A  given  kind 
of  wood  is  always  used  more  if  it  is  widely  distributed  and  easily 
available. 


CHAPTER  III 

WOOD.  CHARACTER  AND  ARRANGEMENT  OF  WOOD-ELEMENTS. 
INFLUENCE  OF  CELLULAR  STRUCTURE  UPON  CHEMICAL 
COMPOSITION  AND  PHYSICAL  PROPERTIES  OF  WOODS. 
IDENTIFICATIONS.  STATEMENTS  OF  WEIGHTS  AND  MODULI 
EMPLOYED  IN  TABULAR  DESCRIPTIONS  OF  SPECIES 

Wood  is  the  solid  part  of  trees — the  part  which,  when  otherwise 
suitable,  is  used  in  construction.  It  consists  of  a  ground-work  of 
starch-like  substance  known  as  cellulose,  permeated  by  materials 
collectively  known  as  lignin.  There  are  also  secretions,  such  as 
resin,  coloring-matter,  and  water.  The  small  proportion  of 
mineral  in  wood  is  evident  as  ash. 

Wood,  timber,  and  lumber  may  not  mean  the  same.  Prop- 
erly speaking,  all  woody  tissue  is  wood;  but  roots  and  branches 
contain  much  wood  that  is  not  suitable  for  construction.  Wood 
that  is  suitable,  although  not  necessarily  ready,  for  construc- 
tion, is  "timber;"  and  wood  that  is  not  only  suitable,  but  also 
ready  for  construction,  is  "lumber."  The  word  timber  may 
thus  include  living  trees  in  the  forest,  as  well  as  logs  and  shaped 
pieces;  whereas,  lumber  refers  only  to  boards,  planks,  beams, 
and  other  sawn  pieces  of  limited  sizes,  and  then  only  in  America. 
The  term  lumber,  which  is  not  sharply  definable,  is  not  used 
much  outside  of  North  America. 

Wood  is  composed  of  innumerable  minute  structural  units, 
known  as  wood-cells,1  or  wood-elements,  which  differ  from  one 

1  So  named  by  Robert  Hooke  in  1667  because  of  resemblance  to  cells  of 
honeycombs. 

REFERENCES. — "Structure  of  Certain  Timber  Ties,"  Dudley  (United 
States  Forest  Division,  Bulletin  No.  1,  p.  31);  "Timber,"  Roth  (United 
States  Forest  Division,  Bulletin  No.  10);  "The  Decay  of  Timber,"  von 
Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin  No.  14,  p.  12); 
"Trans.  American  Railway  Engineering  Association,"  Tiemann  (Bulletins 
No.  107  and  No.  120);  "Plant  Anatomy,"  Stevens;  "Identification  of 
Economic  Woods  of  United  States,"  Record  (John  Wiley  &  Sons,  1912); 
"Wood,"  Boulger  (London,  Second  Edition);  "North  American  Gymno- 
sperms,"  Penhallow;  "Outlines  of  Botany,"  Leavitt;  "Pithray  Flecks  in 
Wood,"  Brown  (United  States  Forest  Service  Circular  No.  215);  etc. 

17 


18 


ORGANIC  STRUCTURAL  MATERIALS 


another  in  shapes  and  sizes,  in  the  thickness  and  surfaces  of  their 
walls,  and  in  the  ways  in  which  they  are  arranged.  There  are 
also  compounds  associated  with,  although  actually  foreign  to,  the 
wood-elements.  Of  these  associated  materials,  water  is  the  most 
important. 

The  subject  is  fundamentally  important.     Physical  properties, 
such  as  hardness,  elasticity,  and  weight  are  influenced  by  (1)  the 


FIG.  9. — Pits.  A,  Longitudinal  section  through  parts  of  two  adjoining 
walls  w.w.  One  pair  of  bordered  pits  6. p.,  is  shown.  B,  Longitudinal  sec- 
tion through  portions  of  two  adjoining  wood-fibers.  Four  pairs  of  simple 
pits  in  adjoining  walls  are  shown;  only  one  pair  is  marked  s.p.  The  lumen 
of  each  fiber  is  marked  1.  The  walls  are  marked  w.  C,  Cross-section 
through  entire  wood-element,  with  parts  of  walls  of  adjoining  wood- 
elements.  Bordered  pits  are  shown  on  the  right,  and  on  the  left  b. p.  The 
torus  t  is  the  thick  part  of  the  common,  separating,  or  primary  portion  of  the 
wall  also  known  as  the  "middle  lamella."  D,  A  larger  and  more  detailed 
section  through  bordered  pits  shown  in  figure  C.  Two  adjoining  pits  with 
torus  and  pit-canal  are  shown. 

character  of  the  wood-elements,  (2)  the  arrangement  of  the  wood- 
elements,  and  (3)  by  the  characteristics  and  quantities  of  the 
compounds  that  are  associated  with  the  wood-elements. 

WOOD-ELEMENTS. — These  vary  in  details,  but  are  similar 
in  this  regard  that  all  partake  of  the  nature  of  minute  tubes. 
The  cavities  within  the  tubes  are  the  "lumina."  A  cell-cavity, 
or  lumen,  may  be  empty,  or  it  may  contain  water  or  other  com- 
pounds. Wood-elements  are  of  several  kinds,  as  wood-fibers, 


PLATE  I.      ARRANGEMENT  OF  WOOD  ELEMENTS— CROSS  SECTIONS 


(a)  Cross-section  of  Longleaf  Pine  (Pinus  palustris) . 


(6)  Cross-section  of  White  Oak  (Quercus  alba). 

Acknowledgments  to  Bureau  of  Plant  Industry,  United  States  Department  of  Agriculture. 

(Facing  page  18.) 


WOODS— WOOD  ELEMENTS 


19 


tracheids,  vessels,  wood-paren- 
chyma fibers,  and  pith-ray  cells. 
Each  of  these  classes  of  wood-ele- 
ments includes  several  varieties. 

The  walls  of  all  wood-elements  are 
thickened  and  appear  under  the 
microscope  as  double  lines. 

The  young  primary  wall,  is  a 
very  thin,  practically  imperforate 
and  continuous  membrane,  which 
constitutes  the  first  outline  of  the  cell. 
This  membrane  originally  surrounded 
the  protoplasm  and  other  materials 
that  were  contained  within  the  living 
cell. 

The  secondary  thickening  is  laid  on 
later  and  gives  strength  to  the  wood- 
element.  It  is  seldom,  if  ever,  im- 
perforate, but  contains  pits  of  char- 
acteristic shapes.  The  layer  is  some- 
times disposed  in  ridges  on  the  inside 
of  the  cell,  much  as  a  spiral  stair- 
case is  placed  within  a  tower.  This 
structure  is  never  present  within 
wood-fibers,  but  is  occasionally  found 
within  tracheids  and  vessels. 

Holes  or  thin  spots  in  the  walls 
of  wood-elements  are  known  as 
"pits."  Some  pits  are  round,  while 
others  are  elliptical  or  slit-shaped. 
They  are  further  divided  into  what 
are  known  as  "simple  pits"  and 
"bordered  pits."  Pits  are  "simple" 
when  the  walls  that  extend  out  from 
the  middle  lamella  are  nearly  parallel, 
and  they  are  "bordered"  when  the 
walls  that  extend  out  from  the  middle 
lamella  diverge. 

The  bordered  pits  that  are  present 
in  the  walls  of  tracheids,  vessels, 
and  some  wood-fibers,  are  invaria- 


-c.w. 


(Nyssa  sylvaticd). 


gu  _          _  

Wood-fibers  of  black  walnut    (Juglans  nigra). 
indicates  lumen;  s.p.  indicates  simple  pit. 


FIG.     10.— Wood-fibers.        A, 
Wood-fiber  of  white  oak  (Quercus 
alba.)      B,   Wood-fiber  of   black 
C,  Wood-fiber  of  beech    (Fagus   americana).     D, 
c.w.  indicates  cell-wall;  I 


20 


ORGANIC  STRUCTURAL  MATERIALS 


FIG.  11. — Tracheids.  A, 
Tracheid  of  yew  (Taxus 
bacata).  B,  Tracheid  of 
pinon  pine  (Pinus  edulis). 
C,  Tracheid  of  red  oak 
(Quercus  rubra).  D,  Tra- 
cheids of  western  yellow 
pine  (Pinus  ponderosa) . 
b.p.  indicates  bordered  pit; 
s.p.  indicates  spiral. 


bly  paired  exactly  in  position  with  similar  pits  in  the  walls  of  ad- 
joining elements.  They  do  not  open  through,  however,  but  are  closed 
by  partitions  which  exist  in  the  primary  walls  or  "middle  lamellae." 
There  is  usually  a  thickened  disc  in  the  middle  of  the  partition  that 
is  known  as  the  "torus." 

Wood-Fibers. — Ordinary  wood-fibers  are  long,  slender,  com- 
paratively smooth-surfaced,  and  sharp-pointed  wood-elements. 
The  walls  are  thick  and  lignified,  and  the  pits  are  usually  simple; 

that  is,  they  are  without  borders. 
Wood-fibers  are  not  found  in  conif- 
erous woods,  but  are  nearly  always 
present  in,  and  are  regarded  as  char- 
acteristic of  the  so-called  broadleafed 
woods  to  which  they  contribute  much 
strength  and  hardness.  The  wood- 
fibers  also  give  mechanical  strength 
to  the  living  tree  and  probably  con- 
tribute in  some  way  to  the  transporta- 
tion of  water  through  the  tree,  from 
the  roots  to  the  foliage. 

Tracheids  ( Tra-ke-ids).— Tra- 
cheids are  elongated,  taper-pointed 
cells,  with  peculiar  markings,  which 
appear,  either  in  the  form  of  bordered 
pits,  located,  for  the  most  part,  on 
the  radial  surfaces  of  the  tracheids, 
or  else  in  the  form  of  ridges,  variously 
disposed  upon  the  inner  walls.  Tra- 
cheids are  the  wood-elements  upon 
which  coniferous  woods  largely  de- 
pend for  strength.  They  are  charac- 
teristic of  coniferous  woods  and 
although  they  do  exist  in  many  of 
the  broadleafed  woods  are  then  in- 
variably subordinate  to  wood-fibers 
and  vessels. 

Tracheids  serve  in  the  living  tree 
because  they  contribute  to  its  me- 
chanical support,  and  also  because  the 
bordered  pits  are  so  designed  as  to 
assist  very  materially  in  the  conduc- 
tion of  water  through  the  stem  from  the  roots  to  the  leaves. 


b.f>- 


b.p 


WOODS— WOOD  ELEMENTS 


21 


-b.p. 


p.w.- 


The  means  by  which  water  is  thus  raised  has  been  credited  to 
root  pressure,  transpiration,  and  osmotic  pressure.1 

Vessels. — These  compound  structures  are  formed  by  the 
breaking  down  of  partitions  that  exist  between  the  abutting  ends 
of  simpler  or  shorter  structures,  known  as  "vessel-segments." 
Tubes  of  very  considerable  length  are  formed  in  this  manner  and, 
as  is  the  case  with  oak,  are 
often  so  large  in  diameter 
that  they  can  be  seen  with 
.the  unaided  eye.  These 
large  cavities  are  commonly 
referred  to  as  "pores,"  and 
the  vessels  themselves  have 
been  variously  named  by 
plant  anatomists  as  pores, 
canals,  ducts,  tubes,  vasa, 
tracheae,  tracheal-tubes, 
and  fistulae. 

Vessels  Differ  with  Spe- 
cies.— The  central  cavities 
of  lumina  of  the  vessels  of 
some  species  are  open, 
while  those  of  other 
species  are  obstructed  by 
parenchymatous  growths 
known  as  "tyloses."  Air 
can  readily  be  blown 
through  several  feet  of  red 
oak,  even  before  it  has 
been  seasoned,  because  tyloses  are  absent  in  the  vessels  of  this 
species.  On  the  contrary,  a  pressure  of  one  hundred  pounds 
per  square  inch  is  sometimes  insufficient  to  force  air  through  a 
single  inch  of  unseasoned  white  oak,  because  the  vessels  of  that 
species  contain  quantities  of  tyloses. 

A  vessel  increases  in  thickness  by  means  of  layers  that  are  gradually 
deposited  on  its  walls.  Several  layers  of  unequal  thickness  can  often 
be  distinguished  with  the  aid  of  a  powerful  microscope.  The  thick- 
ened portions  of  the  walls  give  strength,  while  the  unthickened  por- 
tions permit  water  and  materials  in  solution  to  pass  in  and  out.  The 
differences  in  thickness  are  evidenced  by  markings  such  as  are  shown 
in  the  picture. 


C 

FIG.  12. — Vessel-segments.  A,  Vessel- 
segment  of  cotton  gum  (Nyssa  aquat- 
ica).  B,  Vessel-segment  of  black  walnut 
(Juglans  nigra).  C,  Vessel-segment  of 
oak  (Quercus).  sc.p.  indicates  scalari- 
form  (ladder-like)  perforations;  b.p.  and 
p.w.  indicate  bordered  pit  and  partition 
wall  respectively. 


1  "Plant  Physiology,"  Jost  (Gibson,  Oxford,  1907,  pp.  45-47.) 


22 


ORGANIC  STRUCTURAL  MATERIALS 


Wood-Parenchyma  Fibers  ( Pa-ren-kih-ma ) .  — These  com- 
paratively short,  compound  structures  are  made  up  of  shorter, 
oblong,  thin-walled  cells,  in  groups,  from  a  few  in  number 
to  as  many  as  eight  or  ten,  of  which  the  upper  and  lower  cells 
are  taper-pointed.  Wood-parenchyma  fibers  resemble  fibers  and 
tracheids  in  general  form,  but  differ  from  them  in  that,  as  groups 
of  living  cells,  they  contain,  besides  proto- 
plasm, the  various  foods  and  products 
connected  with  the  life-processes  of  the 
tree.  They  may  contain  crystals  of 
calcium  oxalate  or  crystals  of  calcium 
carbonate.  The  cells  that  contain  these 
crystals  are  often  cubical  in  outline  and 
the  cavities  are  sometimes  completely 
filled  with  the  crystalline  mass.  Such 
elements  are  known  as  "idioblasts." 


Wood-parenchyma  fibers  are  usually, 
although  not  always,  shorter  than  wood- 
fibers  in  the  same  species.  They  are  pecu- 
liar, in  that  they  retain  their  power  of  cell- 
division  after  they  leave  the  cambium,  and 
usually  divide  into  a  number  of  short 
parenchyma-cells,  separated  by  horizontal 
or  oblique  partition- walls,  as  has  been 
noted.  There  are  simple  pits  that  on  the 
whole  vary  only  slightly  in  different  species 
of  woods.  Sanio,  author  of  the  term  "  wood- 
parenchyma  fiber,"  describes  them  as  tis- 
sues that  originate  through  the  division  of 
cambium  cells  and  that  conduct  and  store 
up  carbohydrates.  He  divides  them  into 
two  classes,  namely,  septate  and  non-septate 
or  intermediate  wood-parenchyma  fibers. 
The  latter  are  sometimes  difficult  to  dis- 
tinguish from  wood-fibers,  but  usually  have 


A  B 

FIG.  13. — Wood-par- 
enchyma fibers.  A, 
Wood-parenchyma  fiber 
of  white  oak  (Quercus 
alba).  Bj  Wood-paren- 
chyma fiber  of  black 
walnut  (Juglans  nigra). 
w.p.c.  indicates  wood- 
parenchyma  cell;  s.p.  in- 
dicates simple  pit;  c.w. 
indicates  cell-wall;  ex. 
indicates  cell-cavity ;  c. 
indicates  crystal  of  cal- 
cium salts. 


thinner     walls     and     larger     cell-cavities. 

Solereder  classifies  wood-parenchyma  fibers  with  wood-fibers,  vessels, 
and  tracheids,  under  the  general  term  "  wood-prosenchyma, "  and  not 
with  pith-ray  elements.1 


igee  also  "Wood,"  Boulger  (Second  Edition,  pp.  28  and  29);  "North 
American  Gymnosperms,"  Penhallow  (p.  109). 


PLATE  II.    ARRANGEMENT  OF  WOOD  ELEMENTS— TANGENTIAL 

SECTIONS 


(a)  Tangential  Section  of  Longleaf  Pine  (Pinus  palustris). 


(b)  Tangential   Section  of  White  Oak  (Quercus  alba)  showing  large  Pith 

Ray. 

Acknowledgments  to  Bureau  of  Plant  Industry,  United  States  Department  of  Agriculture. 


WOODS— WOOD  ELEMENTS 


m.r.c.  - 


rt 


t 

©_ 

© 

-re: 


~r.t 


C  D 

FIG.  14. — Pith-rays.  A  and  J5,  rPith-rays  in  radial  and  tangential  sec- 
tions of  black  walnut  (Juglans  nigra).  C  and  D,  Pith-rays  in  radial  and 
tangential  sections  of  western  yellow  pine  (Pinus  ponderosa).  p.r.  indi- 
cates pith-ray ;  t  indicates  tracheid ;  c.w.  indicates  cell  wall;  r.t.  indicates  ray 
tracheid;  r.c.  indicates  ray  cells;  m.r.c.  indicates  marginal  ray  cell;  s.p.  indi- 
cates simple  pit;  r.d.  indicates  resin-duct;  r.c.  indicates  resin-cell. 


24  ORGANIC  STRUCTURAL  MATERIALS 

Pith-rays. — These  compound  structures  are  made  up  of 
short,  cubical  or  oblong  cells,  arranged  in  rows  that  pass  radially 
from  the  center  of  a  tree  to  its  circumference.  Pith-rays  differ 
strikingly  from  other  wood-elements  in  that  they  are  arranged 
horizontally.  They  cross  the  tree,  bind  the  vertical  wood-ele- 
ments together,  and  also  serve  as  a  vital  link  between  the  living 
elements  of  the  tree.  The  cells  of  which  pith-rays  are  composed 
resemble  those  making  up  wood-parenchyma  fibers  in  form 
and  structure,  and  because  of  the  fact  that  they,  too,  contain 
various  foods  and  products  connected  with  the  life-processes  of 
the  tree.  The  terms  pith-ray,  medullary  ray,  and  ray  mean 
the  same. 

Pith-rays  are  plainly  visible  in  some  woods,  as  oaks,  but  are  not 
easily  visible  in  other  woods,  as  poplars,  even  when  a  hand  magni- 
fying glass  is  employed.  Pith-rays  contribute  to  the  appearance 
of  "quartered  oak,"  which  with  other  " quartered  woods,"  are 
obtained  by  cutting  logs  radially  (see  Fig.  25).  When  cut  in 
this  way  the  pith-rays  are  split  and  their  larger  surfaces  are 
exposed.  Otherwise,  in  the  tangential  cut,  the  pith-rays  are  cut 
through  vertically  and  appear  as  short  lines.  Pith-rays  are  not 
visible  in  some  woods  except  when  very  thin  pieces  are  placed 
under  a  compound  microscope. 

The  small,  cubical  or  oblong  cells,  of  which  pith-rays  are  composed, 
are  indented  with  minute,  simple  pits.  The  pith-rays  of  some  conifers 
also  contain,  in  addition  to  the  small  parenchyma  cells,  one  or  more 
rows  of  peculiar  flattened  tracheids,  known  as  "ray-tracheids."  Resin- 
ducts  are  also  present  in  some  of  the  pith-rays  that  exist  in  the  pines. 
Pith-rays  may  be  divided  into  primary  and  secondary  pith-rays.  The 
first  are  those  that  extend  completely  through  from  the  pith-cavity  at 
the  center  of  the  tree  to  the  bark,  while  the  second  are  those  that  do 
not  extend  through  thus  completely. 

The  function  of  the  pith-ray  has  been  described  as  follows:1 

"The  medullary-rays  have,  for  their  primary  function,  the  radial 
transmission  and  storage  of  food.  Their  intimate  relation  with  the  cells 
of  the  phloem  at  their  outer  and  with  the  xylem  parenchyma  along  the 
inner  course,  and  the  fact  that  we  usually  find  them  gorged  with  food, 
points  to  this  conclusion.  The  short,  vertical  extent  of  the  rays,  and 
their  isolation  from  each  other  renders  them  unsuited  for  the  vertical  or 
longitudinal  transmission  of  foods.  If  they  were  of  value  in  this  respect 
girdling  would  not  prevent  the  downward  flow  of  foods." 

1  "Plant  Anatomy"  Stevens  (p.  162). 


WOODS— WOOD  ELEMENTS 


25 


Resin-canals. — Resin-canals  are  not  wood-elements  like  tra- 
cheids  and  wood-fibers.  On  the  contrary,  they  are  inter- 
cellular passages  which  appear  scattered  irregularly  here  and 
there  throughout  the  woods  of  some  coniferous  trees.  They  are 
not  numerous  and  do  not  form  conspicuous  structural  features 
in  the  cross-sections  in  which  they  occur.  The  continuity  of 
the  passages  through  some  of  these  canals,  as  those  in  Douglas 

Pr 


w.p  c.- 


FIG.  15. — Resin-canal.  Resin-canal  in  transverse  section  of  western 
yellow  pine  (Pinus  ponderosa).  r.c.  indicates  resin-canal;  e.p.c.  epithe- 
lium cells;  w.p.c.  wood-parenchyma  cells;  p.r.  pith-ray;  t.  tracheid;  b.p. 
bordered  pit;  and  c.w.  cross-wall. 

fir,  is  interrupted  by  constrictions.  In  some  woods  resin-canals 
are  simple  cavities  known  as  " cysts."  Resin-canals  and  resin- 
ducts  are  the  same. 

The  resin-passages  that  exist  in  the  trees  that  produce  commercial 
resins  have  received  most  attention.  Tschirch  divides  these  passages, 
as  they  exist  in  the  pines,  into  " primary  resin-ducts "  and  "secondary 
resin-ducts."  The  former,  scattered  through  the  heartwood  and  the 
sapwood,  produce  comparatively  small  quantities  of  resins,  while  the 
latter,  formed  in  the  outer  sapwood  of  trees  that  have  been  wounded, 
pour  crude  turpentine  over  the  wounded  surfaces  in  order  to  protect 
them.  The  turpentine  of  commerce  is  obtained  from  these  "secondary 


26  ORGANIC  STRUCTURAL  MATERIALS 

resin-canals."  It  will  be  seen  that  the  resins  produced  by  the  "  primary 
canals"  are  physiological  products,  whereas  those  produced  by  the  " sec- 
ondary canals"  are  pathological  products.  Tschirch  has  demonstrated 
that  the  seat  of  resin-production  is  in  a  mucilaginous  layer  (epithelium 
cells,  Fig.  15)  that  lines  the  inside  of  the  resin  canal.1 

Arrangement  of  Wood-elements. — The  character  of  wood 
depends  not  only  upon  its  wood-elements  but  also  upon  the 
way  in  which  these  wood-elements  are  arranged.  Most  wood- 
elements  are  arranged  up  and  down,  a  fact  that  explains 
the  comparative  ease  with  which  most  woods  are  split.  But 
besides  this,  there  is  a  horizontal  arrangement.  The  pith-rays 
pass  radially,  that  is  horizontally,  from  the  center  of  the  tree  to 
its  circumference,  and  bind  the  vertical  wood-elements  together. 
The  arrangement  of  wood-elements  is  much  more  regular  in  some 
woods,  as  pines,  than  in  others,  as  eucalyptus  and  lignum vitae; 
and  woods  are  easy  or  difficult  to  work,  in  proportion  as  their 
elements  are  thus  arranged  in  a  simple  or  a  complicated  manner. 

Associated  Compounds. — Certain  materials  are  associated  with, 
although  they  do  not  form  part  of,  the  wood-elements,  and  such 
compounds  are  notable  because  they  exert  a  material  influence 
upon  the  character  of  the  wood-elements,  and,  therefore,  upon 
the  character  of  the  wood.  Of  these  associated  materials,  the 
most  important  is  water,  which  acts  by  distending  the  wood- 
elements  and  thus  making  them  weaker  and  more  pliable.  The 
influence  of  moisture  is  so  great  as  to  require  further  notice  (see 
" Moisture  in  Wood").2 

Influence  of  Cellular  Structure  upon  Chemical  Composition 
and  Physical  Properties  of  Wood. — Chemical  and  physical  prop- 
erties of  woods  are  influenced  by  the  character  and  arrangement 
of  the  wood-elements,  and  by  the  qualities  and  quantities  of  the 
materials  associated  with  these  wood-elements.  Chemical  com- 
position, strength,  weight,  appearance,  and  other  properties  re- 
garded by  those  who  use  woods  depend  much  upon  these  details. 

1  "Resin-Canals  in  White  Fir,"  Mell  (American  Forestry,  June,  1910); 
"Relation  of  Light  Chipping  to  the  Commercial  Yield  of  Naval  Stores," 
Herty  (U.  S.  Forest  Service,  Bulletin  No.  90). 

2  "Sap  in  Relation  to  the  Properties  of  Wood,"  Record  (Proc.  American 
Wood  Preservers  Association,  Baltimore,  Md.,  1913,  pp.  160-166);  "Effect 
of  Moisture  upon  the  Strength  and  Stiffness  of  Wood,"  Tiemann  (United 
States   Forest  Service  Bulletin  No.  70  and  United  States  Forest  Service 
Circular  No.  108). 


WOODS— WOOD  ELEMENTS 


27 


Identification  of  Woods. — External  appearances  differ  and 
are  hard  to  describe.  Colors  vary,  even  in  pieces  cut  from  the 
same  tree ;  moreover,  colors  are  not  permanent,  but  often  change 


FIG.  16. — Dissection  showing  waving  cell  arrangement  in  a  specimen  of 

curly  redwood. 

with  age  and  exposure.  Artisans  become  familiar  with  the 
working  qualities  of  a  few  woods,  but  are  commonly  uncertain 
with  regard  to  the  working  qualities  of  other  woods.  On  the 
whole,  the  character  and  arrangement  of  the  wood-elements 


28 


ORGANIC  STRUCTURAL  MATERIALS 


afford  the  only  reliable  basis  upon  which  many  woods  can  be 
finally  identified.  Some  of  the  cellular  characteristics  of  woods 
are  evident  to  the  naked  eye,  but,  in  most  cases,  the  microscope 
is  required. 

The  cellular  characteristics  of  woods  are  most  evident  in  their 
cross-sections.  The  cross-sections  of  different  species  differ 
from  one  another,  but  each  one  exhibits  certain  traits  that  remain 


FIG.  17. — Photomicrograph  of  spruce  (cross-section).     Thought  to  be  about 

500,000  years  old.1 

constant  for  that  species,  and  in  many  cases  these  traits  are  suffi- 
cient to  serve  as  a  means  of  practical  identification.  For  example, 
it  will  be  noted  that  the  section  of  white  oak  (Plate  I)  contains 
large  vessels  but  is  without  resin-ducts,  whereas  the  section  of  long- 
leafed  pine  (Plate  I)  contains  resin-ducts  but  is  without  vessels. 

footnote,  p.  29. 


PLATE  III. 


ARRANGEMENT  OF  WOOD  ELEMENTS— RADIAL 
SECTIONS 


(a)  Radial  Section  of  Longleaf  Pine  (Pinus  palustris). 


(6)  Radial  Section  of  White  Oak  (Quercus  alba}. 

Acknowledgments  to  Bureau  of  Plant  Industry,  United  States  Department  of  Agriculture. 

(Facing  page  28.) 


WOODS— WOOD  ELEMENTS 


29 


The  identification  of  a  log  removed  from  an  ancient  forest  bed  is 
described  by  Koehler.1  The  extent  and  character  of  the  soil  and  other 
material  deposited  upon  the  log  caused  geologists  to  believe  that  it  was 
500,000  years  old.  The  wood  was  brittle,  and  much  distorted,  most  of 
the  cell-elements  being  flattened.  But  when  under  a  microscope  the 
characteristic  structure  of  the  wood  was  revealed.  The  wood  was  re- 
ported as  Spruce.  (See  Figures  17  and  18.) 


FIG.  18. — Photomicrograph  of  fresh  spruce  (cross-section).1 

Banded  woods  may  be  easily  distinguished  from  non-banded 
woods  by  the  presence  or  absence  of  yearly  bands,  layers,  or  rings 
(Figs.  1  and  2);  while  the-  needleleaf  and  broadleaf  woods,  which 
together  make  up  the  banded  woods,  may  be  told  from  one  an- 
other by  noting  the  differences  shown  in  the  table  that  follows 
(Record2) : 

1  From  "  Wood  Older  than  the  Hills,"  Koehler,  by  Courtesy  of  The  Ameri- 
can Forestry  Magazine,  Washington,  D.  C.  (February,  1916). 

2  "  Identification  of  Economic  Woods  of  the  United  State  \t "  Record  (p.  13). 


30 


ORGANIC  STRUCTURAL  MATERIALS 


BANDED  WOODS 


Needleleaf  Woods,  Softwoods 
(Conifers). 

True  vessels  absent. 

Wood  tracheids  present  and  form- 
ing bulk  of  wood. 

Ray  tracheids  present  or  absent. 

Wood  fibers  absent. 

Wood  parenchyma  present  (ex- 
cept in  Taxacese),  but  usually 
subordinate. 

Ray  parenchyma  present. 


Broadleaf  Woods,  Hardwoods 
(Dicotyledons). 

True  vessels  present. 

Tracheids  present  or  absent;  al- 
ways subordinate. 

Ray  tracheids  absent. 

Wood  fibers  present. 

Wood  parenchyma  present,  and 
very  often  conspicuous. 

Ray  parenchyma  present. 


The  key  prepared  by  Fernow  and  Roth1  is  based  upon  a  divi- 
sion of  banded  woods  into  three  classes,  namely:  non-porous 
woods,  ring-porous  woods,  and  diffuse-porous  woods.  The  dis- 
tinctions are  as  follows: 

1.  Non-porous  Woods. — The  pores  (vessels)  of  these  woods  are  not 
evident,  even  with  magnifiers.     The  annual  layers  are  distinguished  by 
means  of  denser,  dark-colored  bands  of  summer-wood  (see  Fig.  19A). 
This  group  includes  the  pines  and  other  so-called  softwoods. 

2.  Ring-porous  Woods. — The  numerous  pores  (vessels)  are  usually  vis- 
ible even  without  magnifiers.     The  pores  are  collected  in  the  spring 
•deposits,  which  thus  contrast  with  the  denser  summer- woods.     This 
group  includes  oak,  ash,  catalpa,  chestnut,  black  locust,  hickory,  per- 
simmon, and  others  (see  Fig.  19B). 

3.  Diffuse-porous  Woods. — The  numerous  pores  (vessels)  are  not  col- 
lected in  the  spring-wood  as  in  the  case  of  the  ring-porous  woods,  but 
are  scattered  throughout  the  entire  annual  layer.     The  pores  are  not 
usually  visible  without  magnifiers.     This  group  includes  cherry,  maple, 
beech,  black  walnut,  holly,  sycamore,  cottonwood,  and  others.     (See 
Fig.   19C.) 

The  value  of  cross-sections,  which  are  more  serviceable  than 
radial  or  tangential  sections  in  making  microscopic  examinations 
of  woods,  is  influenced  by  the  tools  that  are  used  to  prepare  these 
sections.  Smooth  surfaces  are  desired  and,  therefore,  very  sharp 

1  "Timber,"  Fernow  and  Roth  (United  States  Forest  Service  Bulletin 
No.  10,  pp.  59-83).  See  also  "Identification  of  Economic  Woods  of 
the  United  States,"  Record  (John  Wiley  &  Sons);  "Confusion  of  Technical 
Terms  in  Study  of  Wood  Structure,"  Mell  (Forest  Quarterly,  Vol.  IX,  1911, 
No.  4,  pp.  574-576) ;  "  Wood,"  Boulger  (Second  Edition,  London) ;  etc.  The 
actual  sections  prepared  by  Hough  are  very  helpful.  "The  Jesup  Collection 
of  Woods"  at  the  American  Museum  of  Natural  History  is,  available  for 
those  living  near  New  York  City. 


WOODS— WOOD  ELEMENTS 


31 


tools  should  be  employed.  If  the  tools  are  not  sharp,  the  surfaces 
will  be  rough  and  the  characteristic  features  obscure.  A  shaving 
cut  by  a  well-sharpened  plane  is  sometimes  sufficient,  but,  for 
more  technical  work,  a  microtome  is  necessary.  Sections  should 
be  cut  precisely  at  right  angles  to  the  vertical  axis  of  the  tree, 
since  otherwise  the  rounded  sections  of  the  vessels  appear  as 
ovals. 


A  B  C 

FIG.  19. — Original  photomicrographs.  A,  Cross-section  of  non-porous 
wood  (longleaf  pine).  B,  Cross-section  of  ring-porous  wood  (white  oak). 
C,  Cross-section  of  diffuse-porous  wood  (sweet  gum). 

For  ordinary  examinations,  any  microtomes,  save  those  of 
the  rotary  type,  are  serviceable.  The  instrument  shown  in 
the  picture  gives  excellent  results.  Compound  microscopes 
manufactured  by  the  Bausch  &  Lomb  Optical  Company  of 
Rochester,  and  by  the  Spencer  Lens  Company  of  Buffalo,  are 
very  satisfactory. 


32  ORGANIC  STRUCTURAL  MATERIALS 

Identification  of  Trees. — Trees  are  not  always  easily  iden- 
tified by  laymen.  Forms  in  the  forest  differ  from  those  in  the 
open.  Bark  varies  with  age,  while  leaves  and  fruit  are  often 
lacking  in  the  winter.  Most  laymen  find  it  easier  to  tell  genus 
than  species.  They  know  that  a  tree  is  an  oak,  but  do  not  know 
whether  it  is  a  red  oak  or  a  pin  oak.  Experience  is  required. 
Sargent's  "  Manual  of  the  Trees  of  North  America,"  and  Hough's 
" Handbook  of  Trees  of  the  Northern  States  and  Canada" 


FIG.  20. — Modification  of  Jung-Thoma  microtome  for  cutting  wood,  as 
described  by  Thomson,  University  of  Toronto,  in  Botanical  Gazette,  August, 

iy  lu. 


are  convenient  reference  books,  while  Hough's  "Leaf  Key  to 
Trees"  and  Ernest  Thompson  Seton's  "Foresters'  Manual"  are 
serviceable  in  the  field  in  identifying  trees  that  are  in  summer 
condition.  l 


1See  also  Bibliography. 


WOODS— WOOD  ELEMENTS  33 

WEIGHTS  AND  MODULI.—  It  seems  best  thus  early  to  introduce 
the  two  series  of  weights  and  moduli  to  be  employed  in  the  tabu- 
lar descriptions  of  species  that  form  part  of  succeeding  chapters. 
Further  descriptions  and  the  reasons  for  preferring  these  par- 
ticular series  of  figures  will  be  given  later.  The  figures  referred 
to  are  as  follows : 

First. — Results  of  experiments  conducted  by  the  National  Forest 
Service.  These  figures  occupy  the  leading  spaces  in  the  descrip- 
tions of  species  (Chapters  V,  VI,  VII,  and  VIII)  under  the  titles 
of  "Weight,"  "Modulus  of  Elasticity,"  and  "Modulus  of  Rupture." 
Results  have  not  yet  been  obtained  for  all  of  the  species  thus  de- 
scribed so  that  some  of  the  spaces  set  apart  for  the  figures  reported 
for  the  National  Forest  Service  are  vacant. 

Second. — Results  of  experiments  conducted  by  the  Watertown 
Arsenal  for  the  Tenth  United  States  Census.  These  figures  appear 
in  the  spaces  immediately  following  those  occupied  by,  or  set  apart 
for,  the  National  Forest  Service  figures. 

Weights  are  given  in  pounds,  and  coefficients  in  pounds  per  square 
inch.  Fractions  of  pounds  and  lower  figures  in  coefficients  have 
been  omitted  as  superfluous. l 


JSee  also  Chapter  IX. 


CHAPTER  IV 


BANDED  TRUNKS  AND  WOODS 

(Conifers  and  Dicotyledons) 

The  trunks  from  which  banded  woods  are  obtained  grow  in 
thickness  from  the  outside.  The  new  layers  of  wood  are  deposited 
upon  the  outside  of  others  that  were  formed  before.  Practically 
all  of  the  woods  that  are  used  in  construction  are  of  this  type. 
The  forest  sources  are  widely  distributed,  and  the  numerous 
species  present  an  almost  infinite  range  of  possibilities. 

PARTS  OF  A  BANDED  TRUNK.— A  section  through  a  banded 
trunk  is  made  up  as  follows:  A  point  or  pith-cavity  exists  at 
the  center  of  the  section :  This  pith-cavity  is  surrounded  by  con- 
centric rings  made  up  of  layers  or 
bands  of  heartwood  and  sap-wood, 
which  together  constitute  the  wood, 
or  xylem.  The  entire  section  is 
surrounded  by  bark,  the  succulent, 
fibrous  inner  part  of  which  is  the 
phloem.  The  line  of  separation 
between  the  bark  and  wood  is  the 
cambium.  The  wood-elements, 
the  bands  or  layers  in  which  they 
are  arranged,  and  some  character- 
istics of  the  bark,  the  sapwood,  the 
heartwood,  and  the  pith  are  im- 
portant. 

Wood-elements. — The  character- 
istics of  fibers,  tracheids,  and  other  wood-elements  have  been 
described.  So  far  as  is  known,  there  are  no  wood-elements  that 
are  particularly  associated  with  the  banded  woods  alone.  Some 
wood-elements  may  be  modified  in  certain  cases,  but  the  same 
kinds  exist  in  both  banded  woods  and  non-banded  woods. 

Annual  Bands,  Rings,  or  Layers. — The  wood-elements  that 
stand  vertically  are  arranged  in  concentric  bands  or  layers  one 
of  which  is  formed  every  growing  season  between  the  bark  and 
the  wood  that  was  formed  during  the  preceding  season.  Each 

34 


FIG.  21. — Section  through 
young  stem  of  box  elder.  Pith 
cavity  surrounded  by  three  an- 
nual deposits  of  wood.  The 
whole  enclosed  by  bark,  b.  The 
radiating  lines  p.r.  are  pith-rays. 
The  cambium  is  at  c. 


ANNUAL  DEPOSITS— DEFECTS 


35 


one  of  these  bands  or  layers  encloses  all  of  the  other  bands  or 
layers  that  were  formed  before,  and  each  one  will  eventually  be 
enclosed  by  others  that  are  formed  later.  The  bands  cover  the 
trunk  and  all  of  the  living  branches  of  the  tree. 

A  band  or  layer  is  made  up  of  two,  more  or  less,  well-defined 
parts  as  follows: 

1.  Early  Growth. — This  portion,  sometimes  referred  to  as 
" spring  growth,"  is  formed  at  a  time  of  the  year,  when,  because 
the  leaves  are  unfolding,  there  is  an  increased  demand  for  water. 


FIG.   22. — Instrument  for  removing  cores  to  determine  ages  of  trees.1 

The  more  porous  water  conduction  elements  preponderate  and  as 
a  result  this  part  of  the  band  is  lighter,  softer,  and  more  porous 
than  the  other.  (See  Plate  I,  page  18). 

2.  Late  Growth. — This  portion,  often  referred  to  as  "  summer 
growth,"  is  formed  after  the  leaves  have  been  fully  expanded 
and  when  the  cambium  can  devote  itself  more  exclusively  to  the 
production  of  the  wood-elements  that  contribute  more  to  strength. 
It  is,  therefore,  denser  and  heavier  than  the  other. 

1  The  instrument  shown  in  the  picture  is  manufactured  by  The  Keuffe 
&  Esser  Company  of  New  York. 


36  ORGANIC  STRUCTURAL  MATERIALS 

The  contrasts  that  exist  between  the  porous  early  growth  and 
the  more  compact  later  growth  of  the  preceding  year  serve  to 
define  the  limits  of  the  yearly  bands. 

Bands  exist  in  all  needleleaf  or  softwood  trees  (conifers),  and 
in  all  broadleaf  or  hardwood  trees  (dicotyledons),  which  grow 
where  there  are  alternating  seasons  of  wet  and  dry,  or  heat  and 
cold.  They  also  exist,  but  are  often  correspondingly  less  pro- 
nounced in  localities  where  the  differences  in  seasons  are  less 
marked.  Bands  are  valuable  as  means  by  which  the  ages  of 
trees  can  be  determined,  and,  since  they  vary  in  thickness  from 
year  to  year  as  the  seasons  are  wet  or  dry,  they  also  serve  as  his- 
tory of  the  local  conditions  of  growth. 

The  history  of  a  Redwood  tree,  dating  from  two  hundred  and  seventy- 
one  years  before  the  Christian  Era,  was  reported  by  Professor  Dudley 
to  the  United  States  Senate  through  the  late  Senator  Platt  of  Connecti- 
cut, on  February  11,  1904.  The  record  obtained  by  counting  the  con- 
centric layers  of  growth  on  the  cross-section  of  the  felled  tree  showed 
that  forest  fires  had  occurred  during  the  years  245,  1441,  1580,  and 
'  1797  A.D.  The  last  fire  was  locally  severe,  since  it  had  charred  a  space 
thirty  feet  in  height  and  eighteen  feet  in  breadth.  It  is  needless  to 
state  that  this  tree  was  exceptionally  vigorous  or  it  would  not  have  re- 
covered from  such  a  wound.  The  new  tissue,  as  deposited  upon  the 
outside  of  this  wound,  was  full,  even,  and  continuous. 

The  value  of  the  band,  layer,  or  ring  as  a  means  by  which  age 
can  be  determined  is  indicated  in  the  quotation  that  follows 
(Fernow1) : 

"In  a  young,  sound,  and  thrifty  timber,  the  rings  are  laid  on  with  the 
utmost  regularity,  and  a  cross-section  of  a  stem  furnishes,  therefore,  not 
only  information  as  to  the  age  of  the  given  section,  but  is  a  fair  indicator 
of  the  life-history  of  the  tree,  periods  of  suppression  and  thrift  being 
indicated,  respectively  by  zones  of  correspondingly  narrow  or  broad 
rings.  In  such  timber,  the  countings  along  different  radii  always  give 
the  same  results. 

.  "If,  on  the  other  hand,  the  rings  are  very  old,  especially  if  slow-grown 
stems  are  counted,  it  happens  not  infrequently  that  counting  along  one 
radius  gives  one  to  five  rings  more  than  the  counting  along  some  other 
radius.  The  reason  for  this  is  not  always  apparent;  in  some  cases,  such 
a  difference  in  results  is  due  merely  to  the  inability  of  the  eye  to  detect 


1  "Age  of  Trees  and  Time  of  Blazing  Determined  by  Annual  Rings," 
Fernow  (United  States  Division  of  Forestry,  Circular  No.  16,  pp.  2,  3,  and  6). 


ANNUAL  DEPOSITS— DEFECTS  37 

an  extremely  narrow,  but  otherwise  well-defined  ring,  and  the  error  may 
be  corrected  by  microscopical  examination.  In  other  cases,  however, 
the  difference  is  based  on  the  actual  absence  of  one  or  more  rings  of 
only  a  given  radius,  extremely  unfavorable  circumstances  having  led 
to  failure  of  the  regular  continuous  development  of  these  rings." 

Pith  (Medulla). — Central  pith  areas,  around  which  wood  is 
deposited,  are  more  or  less  evident  in  the  sections  of  young  trees, 
saplings,  and  young  branches.  They  do  not  grow  in  size  after 
the  first  year,  and  in  mature  trees  are  usually  so  compressed  as 
to  be  quite  obscure.  Pith  itself  is  made  up  of  thin- walled  paren- 
chymatous  cells  within  which  food  for  the  rapidly  growing  parts 
is  stored,  at  least  in  the  younger  stems.  The  service  which  pith 
renders  to  the  stem  is  apparently  of  a  temporary  nature. 

Heartwood  (Duramen). — Heartwood  is  modified  sapwood. 
Heartwood  gives  stability  to  the  tree  but  is  not  utilized  in  its 
physiological  processes.  A  tree  can  survive,  even  although  much 
of  its  heartwood  has  decayed  or  been  otherwise  removed.  Heart- 
wood  is  heavier,  tougher,  stronger,  and  darker  than  sapwood. 
Its  cell-structures  are  older  and  its  walls  appear  thicker  through 
the  accumulation  of  deposited  materials.  The  protoplasm  has 
disappeared  and  inert  minerals,  tannin,  gums,  and  pigments  have 
appeared.  The  change  from  sapwood  to  heartwood  goes  for- 
ward rapidly  in  the  trees  of  some  species,  such  as  redwood  and 
locust,  and  the  sections  of  these  trees  appear  to  be  almost  wholly 
heartwood.  In  trees  of  other  species,  the  changes  take  longer. 

Von  Schrenk  believes  that  sapwood  changes  to  heartwood  suddenly; 
that  the  change  does  not  take  place  in  one  ring  every  year,  but  that  it 
frequently  skips  many  years,  so  that  eight,  ten,  or  even  more  rings  may 
change  from  sapwood  to  heartwood  in  one  year.  He  also  calls  attention 
to  the  fact  that  one  side  of  the  tree  may  change  before  the  other,  and 
that  part  of  a  ring  may  be  heartwood,  while  the  rest  remains  sapwood.1 

Sapwood  (Alburnum). — This  is  the  younger,  lighter-colored, 
and  more  porous  wood.  It  is  the  part  that  is  directly  beneath 
the  bark,  the  part  that  later  turns  to  heartwood.  Sapwood  is 
vitally  essential  to  the  life  of  the  tree,  but  is  less  durable,  and 
usually  weaker,  and  less  valued  in  construction  than  heartwood. 
The  cell-elements  are  the  same  as  those  in  heartwood,  but  the 
latter  are  usually  modified,  as  was  noted  in  the  preceding  para- 
graph. Sapwood  is  more  pliable  than  heartwood,  and  the  sap- 

1  United  States  Bureau  Plant  Industry,  Bulletin  No.  14,  p.  15. 


38  ORGANIC  STRUCTURAL  MATERIALS 

woods  of  several  trees,  such  as  hickory  and  ash,  are  preferred  and 
much  valued  for  this  reason.  The  sap  currents  travel  upward 
in  the  sapwood,  hence  the  name. 

The  wood  manufactured  by  a  tree  when  it  is  old  is  usually  softer  and 
weaker  than  that  made  by  the  tree  when  it  is  younger.  Because  of  the 
time  in  the  life  of  the  tree  when  it  is  grown,  the  sapwood  of  a  large 
log  may  be  inferior  in  strength  to  equally  sound  but  older  heartwood 
in  the  log.  The  United  States  Forest  Service1  reports  upon  the  com- 
parative strength  of  sapwood  and  heartwood  as  follows:  "  Sap  wood, 
except  that  from  old,  overmature  trees,  is  as  strong  as  heartwood, 
other  things  being  equal,  and  so  far  as  the  mechanical  properties 
go  should  not  be  regarded  as  a  defect." 

Bark. — This  husk  or  outer  cover  resembles  the  wood,  although 
many  of  its  properties  are  quite  unlike  those  of  wood.  Bark  is 

characteristic  of  exogenous 
trees  and  assists  these  trees 
in  two  ways:  First,  it  is  an 
agent  in  the  physiological 
processes  of  the  tree;  and 
second,  it  affords  protection. 
The  bark  is  made  up  of 
several  parts.  They  are  as 
follows : 

1.  The    phloem,      inner,     or 
FIG.  23.— Compound  structure  of         fibrous    bark,     is     composed 

partly  of  very  long,  thick- 
walled  cell-structures,  known  as  "bast  fibers."  These  are  the  ele- 
ments that  give  character  to  the  stringy  bark  of  the  basswood 
and  the  grapevine,  and  that  form  the  " fiber"  of  flax  from  which  linen 
fabric  is  woven.  These  constitute  the  "hard  bast."  Associated  with 
the  cell-structures  noted  above  are  specialized  elongated  parenchyma- 
cells  with  their  living  contents.  These  constitute  the  "soft  bast";  they 
are  the  sieve  tubes  and  companion  cells  which  serve  as  channels  through 
which  the  elaborated  sap  passes  in  its  journey  from  the  leaves.  These 
parts  together  are  known  as  the  "phloem." 

2.  The  living  or  green  part  in  the  middle,  called  "green  bark"  or 
cortex,  is  largely  composed  of  rounded  parenchyma-cells,  which  contain 
the  green  substance,  chlorophyll,  that  also  exists  in  the  leaves.  The 
green  part  of  the  bark  of  a  twig  resembles  the  substance  of  a  leaf,  in 
that  it  also  is  a  tissue  which  manufactures  elaborated  food.  This  layer 

1  "Tests  of  Structural  Timber"  (United  States  Forest  Service,  Bulletin 
No.  108,  p.  35). 


ANNUAL  DEPOSITS— DEFECTS 


39 


loses  its  green  color  in  older  stems  because  the  surrounding  "  corky 
layer"  is  thick  enough  to  cut  out  all  the  light.  In  the  outer  portion  of 
this  layer  of  green  bark  there  are  developed  regions  of  "cork-cambium," 
which,  by  their  repeated  division,  give  rise  to  the  outermost  or  corky 
layer. 

3.  The  outermost  corky  layer  is  made  up  of  dead  and  empty  cells 
derived  from  the  outermost  cortex  cells,  constituting  the  "cork  cam- 
bium."    The  walls  of  these  cells  are  suberized,  that  is,  they  have  been 
altered  and  rendered  impermeable  to  water  by  the  addition  of  a  sub- 
stance known  as  "suberin,"  or  cork.     This  layer  serves  to  prevent  un- 
due losses  of  fluids  from  the  tree  by  evaporation.     Moreover,  it  is  a 
non-conductor  and  protects  from  the  cold;  it  also  protects  against  the 
entrance  of  disease.     Composed  as  it  is  of  dead  cells,  this  cork  layer 
cannot  expand,  but  is,  usually,  gradually  split  by  the  expansion  of  the 
wood  cylinder  into  ridges  or  scales,  in  characteristic  fashion  for  each 
species,  and  is,  usually,  eventually  worn  away  or  otherwise  lost,  in  large 
part,  from  the  surface  of  the  tree. 

4.  The  epidermis  consists  of  a  single  layer  of  close-fitting,  tabular  cells 
with  thick,  outer  walls.     It  is  impervious  to  water  but  lasts  in  most 
trees  only  during  the  first  year  or  two,  and  is  best  seen  on  the  surfaces 
of  young  stems  or  twigs.     In  smooth-barked  trees,  it  may  live  many 
years. 


-  Cross  Section 


Radial  Cuf 


FIG.  24. — C,   Cross  surface.     R,   Radial  surface.     T7,   Tangential  surface. 


Three  Surfaces  of  Wood. — The  appearance  or  "  grain  "  of  wood 
is  influenced  by  the  way  in  which  it  is  cut.  There  are  three  funda- 
mental surfaces  or  exposures.  They  are  as  follows:  (1)  Cross 
surfaces  in  which  the  markings  appear  as  circles.  This  is  shown 
on  the  surface  C.  (2)  Radial  surfaces  in  which  the  yearly  rings 
are  cut  directly  across  and  appear  as  lines,  as  on  the  surface  R. 
(3)  Tangential  surfaces  in  which  the  surface  is  cut  parallel  to 
the  annual  rings.  Characteristic  tangential  figures  are  shown  on 
the  surface  T. 

Logs  are  sometimes  quartered  and  then  cut  across  the  yearly 
rings.  These  "quarter-sawn"  pieces  are  stronger  and  better 


40 


ORGANIC  STRUCTURAL  MATERIALS 


than  other  pieces,  but  are  more  costly  because  of  the  extra  labor 
and  the  waste.  Edge-grained,  vertical-grained,  straight-grained, 
and  rift-grained  pieces  are  the  same  as  quartered  pieces  when 
these  names  are  applied  to  manufactured  woods.  The  pith-rays 
of  some  woods  are  exposed  by  quartering; 
"  quarter-sawn "  oak  is  attractive  for  this 
reason. 

The  best  effects  in  grain  or  figure  are 
sometimes  obtained  when  pieces  are  de- 
veloped by  what  is  known  as  the  "  rotary 
cut."  This  is  often  the  case  with  the  wood 
of  the  birdseye  maple.  A  revolving  log  of 
the  wood  that  is  to  be  cut  is  advanced 
against  a  tool  that  pares  a  broad,  thin 
ribbon  from  its  surface.  The  ribbons  are  later  used  as  veneers. 


FIG.  25. — One  method 
of  quarter-sawing. 


s  — 


It  should  be  noted  that  grain  and  figure  differ  in  different  pieces  of  the 
same  species.  One  Hard  Maple  tree  (Acer  saccharum)  may  yield  char- 
acterless pieces  that  are  suitable  for  little  else  than  flooring,  while 
another  nearby  tree  of  the  same  species  may  contain  beautiful  birdseye 
or  curly  maple,  suitable  for  costly  cabinet  work. 

Ordinary  planks  and  boards  are  cut  parallel  to  the  diameters 
of  the  logs.  Grain  is  not  regarded  in  these  pieces,  which  are 
used  in  ordinary  construc- 
tions. Such  pieces  are 
known  as  bastard,  slash- 
cut,  or  slice-cut  boards  or 
planks.  The  segments  of 
bark  and  sapwood  that 
are  removed  from  the  out- 
side  of  a  log  are  known  as 
" slabs."  The  uneven  ap- 
pearance of  the  edges  of 
boards  that  have  been  cut 
through  from  one  side  of 
the  log  to  the  other  is  re- 
ferred to  as  "wain."  "Edging"  refers  to  the  uneven  pieces  or 
edges  that  are  removed  when  the  boards  are  cut  down  to 
standard  widths.  Slabs  and  edging  are  worked  into  laths  or 
are  burned  as  fuel. 

DEFECTS. — Defects  are  of  many  kinds.  The  cracks  or 
separations  that  radiate  from  the  centers  of  trees  are  known  as 


FIG.  26.— Ordinary  method  of  sawing  a 
log.  S  represents  slabs;  E  represents 
edging. 


ANNUAL  DEPOSITS— DEFECTS  41 

" heart-shakes "  and  " star-shakes."  The  separations  between 
the  yearly  layers  are  known  as  " cup-shakes."  It  is  assumed 
that  "cup-shakes"  are  influenced  by  the  winds,  which  roll  the 
trees  to  and  fro,  and,  for  this  reason,  the  pieces  in  which  cup- 
shakes  occur  are  referred  to  as  "rolled  lumber."  Separations 


FIG.  27. — Tree  rolled  by  wind. 

caused  by  wind  or  frost  are  "wind-shakes"  or  "frost-shakes" 
and  the  short  but  comparatively  deep  cracks  that  appear  in 
planks  as  a  result  of  rapid  drying  are  known  as  "checks." 

Knots  are  the  Result  of  Branches. — Buds  connected  with  the 
pith-cavity  at  the  center  appear  upon  the  surface  of  the  trunk. 
They  extend  and  eventually  develop  into  branches.  The  adja- 


42  ORGANIC  STRUCTURAL  MATERIALS 

cent  wood-elements  between  the  pith-cavity  and  the  surface  of 
the  trunk  are  disturbed  and  the  result  is  a  knot.  Knots  may  be 
prevented  by  removing  the  buds  while  they  are  small. 

Many  Names  Apply  to  Results  of  Diseases.— Wet-rot,  dry-rot, 
soft-rot,  disease,  decay,  bluing,  rust,  mildew,  canker,  bot, 
dote,  and  other  terms  are  all  thus  employed.  The  results  indi- 
cated by  aJl  of  these  names  are  usually  due  to  the  presence  of 
bacteria  or  fungi.  Wood  that  is  lifeless  and 
brittle  as  the  result  of  disease  is  known  as 
"brashwood,"  a  name  that  is  also  applied  to 
wood  that  has  become  lifeless  and  brittle  as 
a  result  of  age. 

Defects  have  been  described  and  stand- 
ardized by  manufacturers  and  others,  and 
lumber  is  now  classified  and  sold  upon  the 
basis  of  accepted  specifications.  Such  speci- 
fications have  been  prepared  by  the  Hard- 

FIG.    28. — Distortion  wood    Manufacturers'    Association    of    the 
[by  branch.      United    ^^    the    padfic    Co^    Lumber 

Manufacturers'  Association,  the  Yellow  Pine  Manufacturers' 
Association,  and  others.  The  principal  series  of  specifications 
have  been  listed  and  published  under  one  cover  by  the  National 
Government.1  Standards  have  also  been  prepared  by  the 
American  Society  for  Testing  Materials  and  by  the  American 
Railway  Engineering  Association. 

A  Committee  appointed  by  the  American  Society  for  Testing  Mate- 
rials, has  defined  the  several  kinds  of  knots  that  appear  in  structural 
timber  as  follows  (see  Year  Book,  1910) : 

1.  Sound  Knot. — A  sound  knot  is  one  which  is  solid  across  its  face 
and  which  is  as  hard  as  the  wood  surrounding  it;  it  may  be  either  red 
or  black,  and  is  so  fixed  by  growth  or  position  that  it  will  retain  its  place 
in  the  piece. 

2.  Loose  Knot. — A  loose  knot  is  one  not  firmly  held  in  place  by  growth 
or  position. 

3.  Pith  Knot. — A  pith  knot  is  a  sound  knot  with  a  pith  hole  not  more 
than  one-fourth  inch  in  diameter  in  the  center. 

4.  Encased  Knot. — An  encased  knot  is  one  which  is  surrounded  wholly 
or  in  part  by  bark  or  pitch.     Where  the  encasement  is  less  than  one- 

1  "Rules  and  Specifications  for  the  Grading  of  Lumber  Adopted  by  the 
Various  Manufacturing  Associations  of  the  United  States"  (United  States 
Forest  Service  Bulletin,  No.  71). 


PLATE    IV.     INFLUENCE  OF  WIND  UPON  TREES  AT  TIMBER  LINE 


ANNUAL  DEPOSITS— DEFECTS  43 

eighth  inch  in  width  on  both  sides,  not  exceeding  one-half  the  circum- 
ference of  the  knot,  it  shall  be  considered  a  sound  knot. 

5.  Rotten  Knot. — A  rotten  knot  is  one  not  as  hard  as  the  wood  it  is  in. 

6.  Pin  Knot. — A  pin  knot  is  a  sound  knot  not  over  one-half  inch  in 
diameter. 

7.  Standard  Knot. — A  standard  knot  is  a  sound  knot  not  over  one 
and  one-half  inches  in  diameter. 

8.  Large  Knot. — A  large  knot  is  a  sound  knot,  more  than  one  and 
one-half  inches  in  diameter. 

9.  Round  Knot. — A  round  knot  is  one  which  is  oval  or  circular  in  form. 

10.  Spike  Knot. — A  spike  knot  is  one  sawn  in  a  lengthwise  direction; 
the  mean  or  average  width  shall  be  considered  in  measuring  spike  knots. 

All  banded  woods,  and  the  trees  that  yield  them  are  divided 
as  follows: 

1.  The  Coniferous  Series  (Coniferce). — The    terms    softwoods, 
needleleaf  and  evergreen  woods,  which  are  so  often  used  in  con- 
nection with  the  woods  of  this  series,  are  convenient  but  some- 
times inaccurate.     These  names  are  unsatisfactory;  first,  because 
some  of  the  woods  are  actually  very  hard;  second,  because  the 
leaves  of  some  are  broader  than  the  name  " needleleaf"  would 
indicate;  and  third,  because  the  leaves  of  some  drop  away  every 
year  and  are  not  evergreen  as  this  term  is  understood.     The  name 
" conifer"   which  is  best,   includes,   among  others,   the  pines, 
spruces,  firs,  hemlocks  and  cedars. 

2.  The  Broadleaf  Series    (Dicotyledons) .  —  These     woods     are 
often  incorrectly  called  hardwoods  and  deciduous  woods.     The 
first  of  these  terms  is  incorrect,  because  some  of  the  woods  are 
very  soft;  the  second  fails  because  the  leaves  of  some  of  the  trees 
are  persistent  or  evergreen,  rather  than  deciduous.     The  leaves, 
with  netted   veins,   are   comparatively  broad,   and   the   name 
"broadleaf"  is,  on  the  whole,  the  best  of  the  popular  names. 
This   series  includes,   among   others,   the   oaks,   elms,   maples, 
hickorys  and  birches. 


CHAPTER  V 

BANDED  TRUNKS  AND  WOODS  (CONTINUED) 
CONIFEROUS  OR  NEEDLELEAF  SERIES 

Conifers 

Coniferous  trees  cover  large  areas  in  parts  of  Canada  and  the 
United  States.  The  Pines,  Spruces,  Hemlocks,  and  other  so- 
called  softwoods  are  of  this  group. 

Coniferous  woods  are  comparatively  light  in  weight  and  the 
arrangements  of  the  wood-element  is,  on  the  whole,  simpler  than 
in  the  woods  of  the  broadleaf  series.  The  vertical  fabric  is  made 
up  almost  entirely  of  tracheids.  The  preponderance  of  tracheids 
and  the  absence  of  true  vessels  are  characteristic  of  these  woods 
which,  because  of  the  simpler  arrangement  of  the  wood-elements, 
are  comparatively  easy  to  work.  Coniferous  woods  are  pre- 
ferred where  the  demand  is  for  bulk  and  strength  rather  than  fine 
qualities,  and  the  total  requirement  as  to  amount  exceeds  the 
requirement  for  woods  of  the  broadleaf  series.  The  trunks  of 
many  species  yield  very  large,  straight  pieces. 

The  leaves  of  the  coniferous  trees  are  resinous  and  usually 
needlelike  and  evergreen.  The  seeds  are  exposed  on  the  inner 
surfaces  of  woody  scales  arranged,  overlapping  one  another,  in 
what  are  known  as  cones.  As  already  stated,  the  names 
" softwood"  and  " evergreen"  do  not  always  apply  so  that  the 
name  " conifer"  should  be  preferred. 


44 


PINE 

Pinus 

These  woods,  which  were  formerly  plentiful  in  the  districts 
where  the  demands  of  construction  were  the  greatest,  have  been 
more  used  in  carpentry  and  construction  than  any  others.  They 
are  to  the  coniferous  woods  what  oaks  are  to  the  broadleaf  woods; 
and,  in  this  country,  they  yet  stand  to  all  woods  somewhat  as  iron 
does  to  all  metals.  The  pines  are  prized  because  of  qualities, 
such  as  strength,  elasticity,  light  weight  and  working  qualities, 
that  fit  them  for  the  constructions  that  require  the  largest  quan- 
tities of  wood.1 

Pine  trees  have  straight,  solid  trunks,  which,  when  grown  in 
forests,  are  usually  free  from  branches  for  many  feet  up  from  the 
ground.  They  mature  slowly  and  it  is  probable  that,  ultimately, 
some  species  will  survive  only  as  cultivated  trees. 

The  needle-shaped,  evergreen  leaves,  which  are  from  one  inch 
to  fifteen  or  more  inches  in  length,  occur  singly  or  in  clusters 
of  two,  three,  and  five.  Thirty-six  of  the  known  species  grow 
naturally  in  the  United  States.  The  Dantzic  or  Northern  Pine 
(Pinus  sylvestris)  is  an  important  European  species.  Pines  are 
often  divided  into  "soft  pines"  and  "hard  pines." 

Soft  Pines. — The  woods  that  form  this  group  are  soft, 
light,  rather  weak,  clean,  uniform,  easily  worked,  and  compara- 
tively free  from  knots  and  resin.  The  yearly  bands  are  less 
pronounced  than  in  the  hard  pines.  Many  resin-ducts,  that 
are  often  plainly  visible  without  the  microscope,  are  distributed 
over  the  sections.  The  Soft  Pines  may  be  divided  according 
to  their  sources  into  White  Pine  (Pinus  strobus)  on  the  one  hand, 
and  Sugar  Pine  (Pinus  lambertiana)  with  some  minor  species  on 
the  other  hand. 

White  Pine  (Pinus  strobus}.  This  tree,  formerly  the  principal  eco- 
nomic tree  of  North  America,  grows  in  the  northern,  central,  and  eastern 
portions  of  the  United  States.  It  formed  the  basis  of  the  early  forest 
resources  of  Maine  and  Michigan,  and  methods  devised  to  cut  and  trans- 

1  See  also  "Uses  of  Commercial  Woods  of  United  States:  2,  Pines"  (United 
States  Forest  Service,  Bulletin  No.  99,  1911). 

45 


46  ORGANIC  STRUCTURAL  MATERIALS 

fer  the  logs  have  influenced  logging  practices  in  all  subsequently  devel- 
oped fields.  White  Pine  was  once  the  only  soft  wood  seriously  consid- 
ered by  lumbermen  in  the  north,  and,  until  as  late  as  the  beginning  of 
the  present  century,  it  supplied  about  thirty  per  cent,  of  all  the  lumber 
that  was  used  in  this  country.1  No  other  wood  known  to  man  has  been 
more  valuable.  There  are  no  perfect  substitutes,  although  sugar  pine, 
spruce,  fir,  redwood,  and  even  whitewood  are  used  in  its  stead. 

Sugar  Pine  (Pinus  lambertiana) .  These  trees  grow  at  high  elevations 
in  parts  of  Oregon  and  California.  The  soft,  coarse,  clean  wood  can 
be  used  in  place  of  true  White  Pine.  Some  of  the  trees  are  very  large. 
Other  minor  American  sources  and  localities  are  as  follows:  White  Pine 
(P.  flexilis),  Rocky  Mountain  Region;  White  or  Silver  Pine  (P.  monti- 
cola),  Pacific  Coast  Region;  Whitebark  Pine  (P.  albicaulis},  Pacific  Coast 
Region;  Mexican  White  Pine  (P.  strobiformis) ,  Arizona  into  Mexico; 
Parry's  Pine  (P.  quadrifolia),  Southern  California;  Nut  Pine  (P.cem- 
broides),  Arizona  into  Mexico. 

Hard  Pines. — These  differ  from  soft  pines  in  that  they  are 
harder,  stronger,  heavier,  more  resinous,  of  a  deeper  color,  and 
more  difficult  to  work.  The  yearly  bands  are  pronounced. 
Large-sized  pieces  of  Hard  Pine  can  be  obtained.  The  principal 
supplies  are  obtained  from  the  Longleaf  Pine  (Pinus  palustris), 
the  Shortleaf  Pine  (Pinus  echinata),  the  Cuban  Pine  (Pinus 
heterophylla) ,  and  the  Loblolly  Pine  (Pinus  tceda). 

Longleaf  Pine  (Pinus  palustris).  This  is  the  principal  tree  of  the 
Hard  Pine  group.  The  wood,  which  is  the  strongest  native  construc- 
tion wood  obtainable  in  large-sized  pieces  in  the  United  States,  is  used 
in  docks,  trestles,  and  other  heavy  constructions.  The  trees  yield  tur- 
pentine, tar,  and  resin.  They  are  usually  tapped  a  few  times  and  are 
then  felled  and  cut  up  into  lumber. 

The  woods  of  the  Cuban,  Shortleaf,  and  Loblolly  Pines  are  so  nearly 
like  that  of  the  Longleaf  Pine,  that  it  is  often  hard  to  tell  them  from 
that  wood  or  from  one  another.  Either,  or  all  of  these  woods  may  thus 
be  delivered  in  response  to  a  demand  for  Southern  Hard  Pine.  It 
should  be  noted,  however,  that  pieces  of  Southern  Hard  Pine  may  now 
be  graded  without  difficulty  by  means  of  the  so-called  Density  Rule2; 
and  the  results  obtained  by  following  this  practical  rule  show  that  the 
strength  of  pieces  of  Longleaf,  Shortleaf,  Loblolly,  and  other  kinds  of 
Southern  Hard  Pine  depend  less  upon  distinctions  due  to  species  than 
upon  relative  densities  of  individual  pieces. 

1Roth  (United  States  Forestry  Bulletin  No.  22,  p.  73);  "White  Pine 
Timber  Supplies"  (United  States  Senate  Doc.  55-1,  Vol.  IV). 
2  See  Index  "Density  Rules." 


CONIFEROUS  TRUNKS  AND  WOODS 


47 


Much  of  the  "Hard  Pine"  used  on  the  Pacific  Coast  is  derived  from 
the  Douglas  Spruce  or  "Oregon  Pine"  (Pseudotsuga  taxifolia).  The 
species  of  pine  may  be  distinguished  from  one  another  by  differences 
that  exist  between  their  leaves  and  cones.  These  are  as  follows:1 


Names 

Leaves 

Cones 

Number  in 
cluster 

Length 

Diameter 
(open) 

Length 

Longleaf  pine  (P.  palustris)  .  . 
Cuban  Pine  (P.  heterophylla) 
Shortleaf  Pine  (P.  echinata).. 
Loblolly  Pine  (P.  taeda)  

2  or  3 
2  or  3 
2  or  3 
3 

10  to  15  in. 
8  to  12  in. 
2  to  5  in. 
5  to  10  in. 

4  to  5  in. 
3  to  5  in. 
1  to  2  in. 
2  to  3  in. 

6  to  10  in. 
4  to    7  in. 
2  in. 
3  to    4  in. 

Tar,  turpentine,  and  resin,  which  are  included  in  what  are  known  as 
"  naval  stores,"  are  derived  principally  from  the  Longleaf  and  Cuban 
Pine  trees.  The  quantities  of  naval  stores  that  are  contained  in  these 
trees  vary  with  individuals.  From  five  to  twenty  per  cent,  of  the  dry 
weight  of  the  heartwood  may  be  due  to  resin.  There  is  less  resin  in 
sap  wood.  The  resin  in  pine  is  known  as  rosin. 

An  exhaustive  investigation2  has  proved  that  strength,  weight,  and 
shrinkage  are  not  influenced  by  "bleeding,"  and  that  "bled"  lumber  is 
as  good  as  lumber  that  has  not  been  "bled."  The  Louisville  &  Nash- 
ville Railroad  once  specified  "unbled"  lumber.  Some  bled  pieces  were 
included  by  error.  The  mill  offered  to  take  them  back  again  if  they 
could  be  separated  from  the  others.  This  proved  to  be  impossible  and 
the  matter  was  dropped. 


Confusion  exists  in  regard  to  the  names  of  the  pines.  All 
Southern  Pines  are  known  commercially  as  Yellow  Pines.  Ameri- 
can White  Pine  is  known  as  Yellow  Pine  in  Europe,  where  all 
Hard  Pines  are  often  referred  to  as  Pitch  Pines.  Spruce  Pine, 
Bull  Pine,  and  Bastard  Pine  are  names  frequently  used  to  hide 
ignorance.  The  species  palustris  has  thirty  local  names.  Botan- 
ical names  should  be  used  to  designate  these  as  well  as  other 
trees. 

1  See  also  "Timber  Pines  of  the  Southern  United  States"  (United  States 
Forest  Service,  Bulletin  No.  13,  1897);  "Properties  and  Uses  of  the  Southern 
Pines"  (United  States  Forest  Service,  Circular  No.  164,  1909);  "Relation  of 
Light  Chipping  to  the  Commercial  Yield  of  Naval  Stores,"  Herty  (United 
States  Forest  Service,  Bulletin  No.  90, 1911);  "The  Naval  Stores  Industry," 
Schorger  and  Betts  (United  States  Department  of  Agriculture,   Bulletin 
No.  229);  etc. 

2  United  States  Bureau  of  Forestry,  Bulletins    No.  8  and  No.  10. 


48  ORGANIC  STRUCTURAL  MATERIALS 

White  Pine.  Pinus  strobus  Linn 

NOMENCLATURE  (Sudworth).  Soft  Pine  (Pa.). 

White  Pine  (local  and  common         Northern  Pine  (N.  C.). 

name).  Spruce  Pine  (Tenn.). 

Weymouth  Pine  (Mass.,  S.  C.).          Pumpkin  Pine. 

Patternmaker's  Pine. 
LOCALITIES. 

North-central  and  northeastern  United  States,  northward  into  Canada; 
southward  along  the  coast  to  New  Jersey,  and  along  the  Alleghenies 
into  Georgia;  also  Illinois. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  and  fifty  feet  in  height;  three  to  six  feet  in 
diameter;  sometimes  larger;  erect  impressive  form;  tufts  of  five, 
slender,  evergreen  leaves  in  long  sheaths;  cones  four  to  six  inches  long, 
one  inch  thick,  slightly  curved;  the  cone-scales  are  without  prickles. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  cream  white;  sapwood  nearly  white;  close,  straight  grain; 
compact  structure;  comparatively  free  from  knots  and  resin. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft  and  uniform;  seasons  well,  is  easy  to  work,  nails  without  splitting, 
and  is  quite  durable  in  exposed  positions ;  one  of  the  lightest  and  weakest 
of  eastern  United  States  pines;  shrinks,  swells  and  warps  less  than 
other  pines;  receives  paints  well. 

REPRESENTATIVE  USES  OF  WOOD. 
Carpentry,  construction,  matches,  spars,  boxes,  and  numerous  other  uses 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
24  (United  States  Forestry  Division).1 
24. 

MODULUS  OF  ELASTICITY. 

1,390,000  (average  of  130  tests  by  United  States  Forestry  Division).1 
1,210,000. 

MODULUS  OF  RUPTURE. 

7,900    (average  of   120    tests    by    United   States    Forestry    Division,)1 
8,900. 

REMARKS. 

Formerly  the  chief  lumber  tree  of  the  United  States.  The  stand  "is 
rapidly  diminishing.  Besides  its  natural  enemy  the  lumberman,  the 
White  Pine  is  seriously  threatened  by  a  disease  known  as  the  "White  Pine 
Blister  Rust." 


lSee  p.  33.  See  also  "The  White  Pine,"  Spaulding  (United  States 
Forestry  Bulletin  No.  22);  "White  Pine — a  Study,"  Pinchot  (Century  Com- 
pany); "White  Pine  Timber  Supplies"  (United  States  Document  No.  40, 
Senate,  551,  Vol.  IV);  "White  Pine,"  Pinchot  (United  States  Forest  Serv- 
ice, Circular  No.  67,  1907),  "The  White  Pine,"  Detwiler  (American  For- 
estry, July,  1916). 


CONIFEROUS  TRUNKS  AND  WOODS  49 

White  Pine.  Pinus  flexilis  James 

NOMENCLATURE  (Sudworth). 

White  Pine  (Cal.,  Nev.,  Utah,  Bull  Pine  (Col.). 

Col.,  N.  M.).  Western  and  Rocky  Mountain  White 
Pine  (Utah,  Mont.).  Pine  (Cal.). 

Limber  Pine.  Limber-twig  Pine. 

Rocky  Mountain  Pine.  Arizona  Flexilis  Pine. 

LOCALITIES. 

Rocky  Mountains,  Alberta  to  Texas  and  southwestern  California. 

FEATURES  OF  TREE. 

Forty  to  fifty  feet  in  height;  one  to  three  feet  in  diameter;  tufts  of  five 
rather  short,  rigid  leaves  in  sheaths;  the  leaves  are  not  more  than  two 
and  one-half  inches  in  length;  the  oval  or  cylindrical  cones  are  about 
four  inches  in  length. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light,  clear  yellow,  turning  red  upon  exposure;  sapwood 
nearly  white;  close-grained;  compact  structure;  numerous  and  con- 
spicuous medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light  and  soft;  saws,  planes,  nails,  and  receives  paints  well;  fairly  durable; 
similar  to  White  Pine  (Pinus  strobus). 

REPRESENTATIVE  USES  OF  WOOD. 
Construction.     Similar  to  White  Pine  (Pinus  strobus). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

27. 
MODULUS  OF  ELASTICITY. 

960,000. 
MODULUS  OF  RUPTURE. 

8,800. 
REMARKS. 

This  tree  forms  mountain  forests  of  considerable  extent. 

1  See  also  "Limber  Pine,  Pinus  flexilis"  James  (United  States  Forest  Serv- 
ice, Silvical  Leaflet  No.  46,  1909). 


50  ORGANIC  STRUCTURAL  MATERIALS 

Sugar  Pine.  Pinus  lambertiana  Dougl 

NOMENCLATURE  (Sud worth). 

Sugar  Pine  (local  and  common  Little  or  Great  Sugar  Pine. 

name).  Gigantic  Pine. 

Big  Pine,  Shade  Pine  (Cal.).  White  Pine. 

LOCALITIES. 

Oregon  and  California.     Best  at  high  altitudes  (above  four  thousand  feet). 

FEATURES  OF  TREE. 

One  hundred  to  occasionally  three  hundred  feet  in  height;  fifteen  to  some- 
times twenty  feet  in  diameter;  the  finely  toothed  leaves,  in  tufts  of  five, 
are  about  four  inches  long;  the  cones  are  from  ten  to  eighteen  inches  in 
length  and  contain  edible  seeds;  there  are  sugar-like  exudations;  a 
great  tree;  the  tallest  and  largest  of  all  the  pines. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  pinkish-brown;  sapwood  cream-white;  coarse,  straight- 
grained;  compact  structure;  satiny,  conspicuous  resin-passages.1 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft  and  easily  worked;  resembles  White  Pine  (Pinus  strobus).  In 
fact  this  is  the  "White  Pine"  of  the  Pacific  Coast. 

REPRESENTATIVE  USES  OF  WOOD. 

Carpentry,  interior  finish,  doors,  blinds,  sashes,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

22. 
MODULUS  OF  ELASTICITY. 

1,120,000. 

MODULUS  OF  RUPTURE. 

8,400. 
REMARKS. 

This  is  the  most  impressive  tree  form  of  the  genus.  Some  of  the  Sugar 
Pines  may  be  grouped  as  to  size  with  some  Redwoods  and  other  giant 
trees.  The  Sugar  Pines  grow  at  high  elevations  and  form  extensive 
forests.  The  sugar-like  exudations  contain  a  principle  known  in  medi- 
cine as  "pinite."  The  Sugar  Pine,  as  well  as  the  White  Pine,  is  subject 
to  the  disease  known  as  "Blister  Rust,"  which  bids  fair  to  injure  seri- 
ously the  stands  of  these  trees. 


1  "Sugar  Pine  and  Western  Yellow  Pine  in  California,"  Cooper  (United 
States  Forest  Service,  Bulletin  No.  69,  p.  25,  1906);  "Sugar  Pine,"  Larsen 
and  Woodbury  (United  States  Argricultural  Bulletin,  426,  1916);  "The 
Sugar  Pine,"  Detwiler  (American  Forestry,  May  1,  1917). 


CONIFEROUS  TRUNKS  AND  WOODS  51 

White  Pine.  Pinus  monticola  Dougl 

NOMENCLATURE  (Sudworth). 

White  Pine  (Cal.,  Nev.,  Ore.).  Little  Sugar  Pine,  Soft  Pine  (Cal.). 

Mountain  Pine,  Finger  Gone  Pine     Western  White  Pine. 

(Cal.).  Mountain  Weymouth  Pine. 

Silver  Pine. 

LOCALITIES. 

Montana,  Idaho,  Pacific  States,  and  British  Columbia. 

FEATURES  OF  TREE. 

Eighty  to  one  hundred  and  fifty  feet  in  height;  two  to  three  feet  in  di- 
ameter; sometimes  larger;  foliage  resembles,  but  is  denser  than  that  of 
White  Pine  (Pinus  strobus)',  the  stiff,  bluish-green  needles  are  about 
four  inches  long;  long,  smooth  cones. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  light  brown  or  red;  sapwood  nearly  white;  straight-grained; 
compact  structure;  suggests  White  Pine  (Pinus  strobus). 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 
Lumber. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

24. 
MODULUS  OF  ELASTICITY. 

1,350,000. 
MODULUS  OF  RUPTURE. 

8,600 
REMARKS. 

Found  at  elevations  of  seven  thousand  to  ten  thousand  feet.  Common 
and  locally  used  in  northern  Idaho. 


52  ORGANIC  STRUCTURAL  MATERIALS 

Georgia  Pine,  Hard  Pine,  Yellow  Pine, 
Longleaf  Pine.  Pinus  palustris  Mill 

NOMENCLATURE  (Sudworth). 

Turpentine  Pine.  Florida  Pine. 

Rosemary  Pine.  Florida  Longleaved  Pine. 

North  Carolina  Pitch  Pine.  Southern  Pitch  Pine. 

Southern  Pine.  Southern  Hard  Pine. 

Longleaved  Yellow  Pine.  Southern  Heart  Pine. 

Longleaved  Pitch  Pine.  Southern  Yellow  Pine. 

Long  Straw  Pine.  Georgia  Pitch  Pine. 

Pitch  Pine.  Georgia  Longleaved  Pine. 

Fat  Pine.  Georgia  Heart  Pine. 

Heart  Pine.  Georgia  Yellow  Pine. 

Brown  Pine.  Texas  Yellow  Pine. 

Florida  Yellow  Pine.  Texas  Longleaved  Pine. 

LOCALITIES. 

South  Atlantic  and  Gulf  States,  Virginia  to  Florida,  intermittently. 
FEATURES  OF  TREE. 

Fifty  to  one  hundred  and  twenty  feet  in  height;  one  to  three  feet  in  di- 
ameter; tufts  of  three  leaves,  ten  to  fifteen  inches  long,  in  long  sheaths; 
the  cones  are  usually  at  the  ends  of  the  small  branches;  the  cone-scales 
have  stout,  recurved  prickles.1 
COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood   orange;   sapwood   lighter;   compact   structure;    conspicuous 
medullary  rays;  fine  and  even  appearance  in  cross-section;  quite  uni- 
form; narrow  annual  rings  (twenty  or  twenty-five  per  inch);  wide  sap- 
wood  in  young  trees.1 
STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  tough,  elastic,  durable,  and  resinous;   the  strongest   and 

stiffest  of  Pines.1 
REPRESENTATIVE  USES  OF  WOOD. 

Heavy  constructions,  ship-building,   cars,  docks,  beams,  ties,   flooring, 

house-trim,  and  many  other  uses. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
38  (United  States  Division  of  Forestry).2 
43. 

MODULUS  OF  ELASTICITY. 

2,070,000  (average  of  1,230  tests  by  United  States  Forestry  Division).2 
2,110,000. 
MODULUS  OF  RUPTURE. 

12,600  (average  of  1,160  tests  by  United  States  Forestry  Division).2 
16,300. 
REMARKS. 

One  of  the  best  woods  for  car-building.     One  of  the  principal  lumber  trees 
of  the  Southeast. 

1  American  Forestry  (September,  1915). 

2  See  p.  33. 


CONIFEROUS  TRUNKS  AND  WOODS  53 

Cuban  Pine.  Pinus  caribcea  Morelet;  Pinus 

heterophylla  (Ell.)  Sudivorth 

NOMENCLATURE  (Sudworth). 

Cuban  Pine,   Slash  Pine   (local         Swamp  Pine  (Fla.,  Miss.). 

and  common  names).  Bastard  Pine,  Meadow  Pine,  Spruce 

Pitch  Pine,  She  Pine,  She  Pitch  Pine. 

Pine  (Ga.}  Fla.). 

LOCALITIES. 

Coast  region,  North  Carolina  to  Florida,  westward  to  Louisiana;  also 
Bahamas  and  Western  Cuba. 

FEATURES  OP  TREE. 

Fifty  to  eighty  feet  in  height;  one  to  two  feet  in  diameter;  the  leaves, 
which  are  ten  to  fifteen  inches  long,  are  gathered  in  tufts  of  two  and 
three;  the  laterally  attached  cones  are  four  or  five  inches  long,  and 
have  short,  recurved  prickles. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Resembles  Loblolly  Pine  wood;  the  color  is  dark  straw,  with  tinge  of 
flesh  color;  variable  and  coarse  appearance  in  cross-section;  annual 
rings  are  usually  wide  (ten  or  twenty  per  inch). 

STRUCTURAL  QUALITIES  OF  WOOD. 

Similar  to  those  of  Longleaf  Pine  and  of  selected  pieces  of  Loblolly  Pine 
(Pinus  tceda);  sometimes  more  resinous  than  Longleaf  Pine  (Pinus 
palustris). 

REPRESENTATIVE  USES  OF  WOOD. 

Similar  to  those  of  Longleaf  Pine,  from  which  it  is  seldom  separated. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
39  (United  States  Forestry  Division).1 

MODULUS  OF  ELASTICITY. 
2,370,000  (average  of  410  tests  of  United  States  Division  of  Forestry).1 

MODULUS  OF  RUPTURE. 

13,600  (average  of  410  tests  by  United  States  Division  of  Forestry).1 

REMARKS. 

This  wood  resembles  and  is  marketed  with  Longleaf  Pine  (Pinus  palustris), 
and  also  resembles  Loblolly  Pine  (Pinus  tceda).  Cuban  Pine  trees  repro- 
duce rapidly  and  are  often  large  enough  to  yield  pitch  and  turpentine 
when  they  are  forty  years  of  age.  This  is  important,  since  the  species 
from  which  most  "naval  stores"  are  obtained  are  being  destroyed  so 
rapidly.  The  Cuban  Pine  grows  in  Honduras  and  Cuba,  as  well  as  in 
the  sub-tropical  regions  of  the  United  States.  This  explains  why  it  is 
called  the  Cuban  Pine. 

1  See  p.  33. 


54  ORGANIC  STRUCTURAL  MATERIALS 

Shortleaf  Pine,  Yellow  Pine.  Pinus  echinata  Mill;  Pinus 

mitis  Michx 
NOMENCLATURE  (Sud worth). 

Common    Yellow    Pine,    Hard  Rosemary  Pine  (N.  C.). 

Pine.  Virginia  Yellow  Pine. 

Spruce  Pine  (Del.,  Miss.,  Ark.).  North  Carolina  Yellow  Pine. 

Bull  Pine  (Va.).  North  Carolina  Pine. 

Shortshat  Pine  (Del.).  Carolina  Pine. 

Pitch  Pine  (Mo.).  Slash  Pine. 

Poor  Pine  (Fla.).  Old  Field  Pine. 

Shortleaved  Yellow  Pine  (N.  C.). 

LOCALITIES. 

Staten  Island  to  Florida;  westward  intermittently  to  Illinois,  Kansas, 
and  Texas. 

FEATURE  OP  TREE. 

Sixty  to  sometimes  ninety  feet  in  height;  two  to  sometimes  four  feet  in 
diameter;  a  large,  erect  tree;  small,  lateral  cones  have  minute,  weak 
prickles;  the  leaves  are  about  four  and  one-half  inches  long;  they  are 
usually  gathered  in  groups  of  two;  the  sheaths  are  long. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Resembles  Longleaf  and  Loblolly  Pines;  variable  appearance  in  cross- 
section;  wide  annual  rings  near  heart. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Variable,  usually  hard,  tough,  strong,  durable,  and  resinous;  lighter  than 
Longleaf  and  Loblolly  Pines. 

REPRESENTATIVE  USES  OF  WOOD. 
Lumber  and  construction;  similar  to  Longleaf  Pine  (Pinus  palustris). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
32  (United  States  Forestry  Division).1 
30. 

MODULUS  OF  ELASTICITY. 

1,680,000  (average  of  330  tests  by  United  States  Forestry  Division).1 
1,950,000. 

MODULUS  OF  RUPTURE. 

10,100  (average  of  330  tests  by  United  States  Forestry  Division).1 
14,700. 

REMARKS. 

The  Shortleaf  Pine  yields  considerable  pitch  and  turpentine,  and  is  the 
principal  species  of  northern  Arkansas,  Kansas,  and  Missouri.  2 

iSeep.  33. 

2  "Southern  Pine,"  Mohr  (United  States  Forestry  Circular  No.  12); 
''Timber  Pines  of  Southern  States,"  Mohr  (United  States  Forestry  Bulletin 
No.  13);  "Shortleaf  Pine,"  Mattoon  (United  States  Department  Agriculture 
Bulletin,  308,  1915)  ;  "The  Shortleaf  Pine,"  Detwiler  (American  Forestry, 
September,  1916). 


CONIFEROUS  TRUNKS  AND  WOODS  55 

Loblolly  Pine.  Pinus  tceda  Linn 

NOMENCLATURE  (Sudworth). 

Old  Field  Pine.  Sap  Pine. 

Torch  Pine.  Meadow  Pine. 

Rosemary  Pine.  Cornstalk  Pine  (Va.). 

Slash  Pine.  Black  Pine. 

Longschat  Pine.  Foxtail  Pine. 

Longshucks.  Indian  Pine. 

Black  Slash  Pine.  Spruce  Pine. 

Frankincense  Pine.  Bastard  Pine. 

Shortleaf  Pine.  Yellow  Pine. 

Bull  Pine.  Swamp  Pine. 

Virginia  Pine.  Longstraw  Pine. 

North  Carolina  Pine. 
LOCALITIES. 

Southern  New  Jersey  to  Florida;  westward  intermittently  to  Texas. 

FEATURES  OF  TREE. 

Fifty  to  one  hundred  or  more  feet  in  height;  two  to  sometimes  four  feet 
in  thickness;  leaves  in  groups  of  threes  are  about  six  inches  long;  scales 
of  lateral  cones  have  short,  straight  spines;  a  large  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Resembles  Longleaf  Pine  (Pinus  palustris},  but  is  variable;  coarse  cross- 
sections;  very  wide  annual  rings  (three  to  twelve  per  inch). 

STRUCTURAL  QUALITIES  OF  WOOD. 

Resembles  Shortleaf  Pine  (Pinus  echinata)',  selected  pieces  rank  with 
Longleaf  Pine  (Pinus  palustris).1 

REPRESENTATIVE  USES  OF  WOOD. 

Used  with  other  Southern  pines;  inferior  in  uniformity,  strength,  and 
durability. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
33  (United  States  Forestry  Division).2 
33. 

MODULUS  OF  ELASTICITY. 

2,050,000  (average  of  660  tests  by  United  States  Forestry  Division).2 
1,600,000. 

MODULUS  OF  RUPTURE. 

11,300  (average  of  650  tests  by  United  States  Forestry  Division).2 
12,500. 

REMARKS. 

These  trees  grow  naturally  on  deforested  land,  whence  the  name  of  Old 
Field  Pine.  A  source  of  abundant  and  cheap  material.  A  vigorous, 
prolific  grower,  probably  one  of  the  pines  of  the  future. 

1  "Loblolly  Pine  in  eastern  Texas,"     Zon  (United  States  Forest  Service, 
Bulletin  No.  64,  1905). 

2  See  p.  33. 


56  ORGANIC  STRUCTURAL  MATERIALS 

Bull  Pine,  Yellow  Pine,  Western 
Yellow  Pine.  Pinus  ponderosa  Laws 

NOMENCLATURE  (Sudworth). 

Big  Pine.  Heavy-wooded  Pine. 

Longleaved  Pine.  Western  Pitch  Pine. 

Red  Pine.  Heavy  Pine  (Cal.). 

Pitch  Pine.  Foothills  Yellow  Pine. 

Southern  Yellow  Pine.  Montana  Black  Pine. 

LOCALITIES 

Rocky  Mountains;  westward  intermittently  to  Pacific  Ocean;  always  at 
elevations  of  eighteen  hundred  or  more  feet. 

FEATURES  OF  TREE. 

One  hundred  to  sometimes  three  hundred  feet  in  height;  six  to  sometimes 
twelve  feet  in  diameter;  thick,  deeply  furrowed  bark;  the  leaves,  which 
are  in  tufts  of  twos  and  threes,  are  from  five  to  nine  inches  long;  the 
conical  cones  are  at  the  ends  of  small  branches;  the  scales  are  tipped  with 
prickles.1 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

The  thin  heartwbod  is  light  red;  sapwood  nearly  white;  rather  coarse 
grain;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Variable,  heavy,  hard,  strong,  and  brittle;  not  durable. 

REPRESENTATIVE  USES  OF  WOOD. 
Lumber,  railway  ties,  mine-timbers,  fuel,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

29. 
MODULUS  OF  ELASTICITY. 

1,260,000. 
MODULUS  OP  RUPTURE. 

10,200. 
REMARKS. 

These  trees  are  often  killed  by  tree-boring  beetles  (Dendroctonus  ponder- 
osa), and  the  wood  of  trees  thus  attacked  eventually  assumes  a  bright 
blue  color  (see  also  von  Schrenk,  United  States  Bureau  of  Plant  In- 
dustry, Bulletin  No.  36).  The  specific  name  ponderosa  was  given 
because  of  the  great  size  of  the  trees. 

1  "Western  Yellow  Pine  in  Arizona  and  New  Mexico,"  Woolsey  (United 
States  Forest  Service,  Bulletin  No.  101,  1911).  "Western  Yellow  Pine 
in  Oregon,"  Munger  (United  States  Department  of  Agriculture,  Bulletin 
No.  418,  1917). 


CONIFEROUS  TRUNKS  AND  WOODS  57 

Norway  Pine,  Red  Pine.  Pinus  resinosa  Ait 

NOMENCLATURE  (Sudworth). 

Norway  Pine,  Red  Pine  (local  and         Hard  Pine  (Wis.). 
common  names).  Canadian  Red  Pine  (Eng.). 

LOCALITIES. 

Southern  Canada,  northern  United  States  from  Maine  to  Minnesota; 
Pennsylvania. 

FEATURES  OF  TREE. 

Sixty  to  ninety  feet  in  height;  one  to  three  feet  in  diameter;  reddish  bark 
on  branchlets;  leaves  are  in  twos  from  long  sheaths;  the  cones  are  at 
the  ends  of  the  branches;  the  scales  are  not  prickle-tipped;  a  tall, 
straight  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

The  thin  heartwood  is  light  red;  sapwood  yellow  to  white;  numerous  pro- 
nounced medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  hard,  elastic,  not  durable,  and  resinous. 

REPRESENTATIVE  USES  OF  WOOD. 

Piles,  telegraph  poles,  masts,  flooring,  and  wainscoting. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
31  (United  States  Forestry  Division).1 
30. 

MODULUS  OF  ELASTICITY. 

1,620,000  (average  of  100  tests  by  United  States  Forestry  Division).1 
1,600,000 

MODULUS  OF  RUPTURE. 

9,100  (average  of  95  tests  by  United  States  Forestry  Division).1 
12.500. 

REMARKS. 

In  spite  of  the  specific  name  resinosa,  which  signifies  resinous,  these  trees 
yield  unimportant  quantities  of  turpentine  and  resin.2 

1  See  p.  33. 

2  "Red    or    Norway   Pine,   Pinus  resinosa  Ait,"  (United  States  Forest 
Service,  Silvical  Leaflet  No.  43,  1909);  "Norway  Pine  in  the  Lake  States," 
Woolsey  (United  States  Department  of  Agriculture,  Bulletin  No.  139,  1914). 


58  ORGANIC  STRUCTURAL  MATERIALS 

Pitch  Pine.  Pinus  rigida  Mill 

NOMENCLATURE  (Sud worth). 

PitchPine  (local  and  common  name)  Yellow  Pine  (Pa.). 

Longleaved  Pine,  Longschat  Pine  Black  Pine  (N.  C.). 

(Del.).  Black  Norway  Pine. 

Hard  Pine  (Mass.).  Rigid  Pine,  Sap  Pine. 

LOCALITIES. 

New  Brunswick  to  Ontario  and  Ohio,  southward  to  northern  Georgia  and 
Alabama;  the  predominant  tree  of  the  New  Jersey  " pine-barrens." 

FEATURES  OP  TREE. 

Forty  to  sometimes  eighty  feet  in  height;  one  to  sometimes  three  feet 
in  diameter;  the  rigid,  flattened  leaves,  which  are  three  and  one-half  to 
five  inches  long,  are  in  groups  of  threes;  the  sheaths  are  short;  the  cones 
are  compact;  the  reddish  scales  have  stout,  recurved  prickles. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown  or  red;  thick  sapwood  yellow  to  nearly  white; 
coarse,  conspicuous  grain;  compact  structure;  very  resinous. 

STRUCTURAL  QUALITIES  OP  WOOD. 
Light,  soft,  not  strong,  and  brittle. 

REPRESENTATIVE  USES  OP  WOOD. 
Coarse  lumber,  fuel,  and  charcoal. 

WEIGHT  OP  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

32. 
MODULUS  OP  ELASTICITY. 

820,000. 
MODULUS  OF  RUPTURE. 

10,500. 
REMARKS. 

In  North  America  the  name,  "Pitch  Pine"  is  sometimes  misleadingly  used 
to  include  all  Hard  Pines ;  abroad,  it  is  sometimes  made  to  include  White 
Pine.  So  much  resin  is  present  that  Pitch  Pine  is  not  greatly  valued  in 
construction.  In  spite  of  this  fact,  the  trees  are  not  relied  upon  for 
naval  stores.  The  trees  are  hardy.  They  sometimes  grow  on  rocks 
or  on  sand  near  the  ocean  where  they  survive  in  spite  of  occasional 
inundations. 


CONIFEROUS  TRUNKS  AND  WOODS  59 

Northern  Pine,  Scotch  Pine,       D .  ,        .    T  . 

_     .  .    _.  Pinus  sylvestns  Linn 

Dantzic  Pine. 

NOMENCLATUKE. 

Dantzic   Fir    (from   place    of   ship-  Swedish  Fir. 

ment).  Scots  or  Scottish  Fir. 

Rigi  Fir  (from  place  of  shipment).  Northern  Fir. 

Memel  Fir  (from  place  of  shipment).  Redwood,  Yellow-wood. 

Stettin  Fir  (from  place  of  ship-  Deal  (local). 

ment). 

LOCALITIES. 

Widespread  in  Europe,  as  Scotland,  Germany,  and  Russia;  also  Asia. 
r.      Cultivated  in  the  United  States. 

FEATURES  OF  TREE. 

Fifty  to  one  hundred  feet  in  height;  two  to  five  feet  in  diameter;  sometimes 
larger;  the  leaves,  which  are  about  four  inches  in  length,  are  slightly 
twisted,  and  are  gathered  in  tufts  of  twos  and  threes;  the  cones  are  at 
the  ends  of  the  small  branches;  the  scales  are  not  prickle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  reddish  white  to  yellowish  white;  sapwood  similar;  even, 
straight  grain  (varies  with  locality). 

STRUCTURAL  QUALITIES  OF  WOOD. 

Moderately  light,  hard,  tough,  and  elastic;  easily  worked  (varies  with 
locality). 

REPRESENTATIVE  USES  OF  WOOD. 
Carpentry,  construction,  planks,  beams,  masts,  and  heavy  timber.1 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
34  (Laslett)  (varies  with  locality). 

MODULUS  OF  ELASTICITY. 

1,680,000  (Laslett)  (varies  with  locality). 
1,800,000  (Thurston). 

MODULUS  OF  RUPTURE. 
7,000  (Thurston)  (varies  with  locality). 

REMARKS. 

This  is  the  principal  softwood  produced  by  the  forests  of  Europe.  The 
trees  are  widely  distributed.  The  Dantzic  and  Rigi  forests  produce  the 
best  wood.  Wood  "equal  to  Dantzic  Fir"  is  sometimes  specified.  The 
wood  suggests  true  White  Pine  (Pinus  strobus). 

1  "Scotch  Pine"  (Pinus  sylvestris),  Pinchot  (United  States  Forest  Service, 
Circular  No.  68,  1907). 


60  ORGANIC  STRUCTURAL  MATERIALS 

The  Stone  Pine  (Pinus  cembra,)  which  is  said  to  be  best  de- 
veloped in  Switzerland,  yields  a  smooth,  fine-grained  wood  which 
suggests  true  White  Pine.  This  wood  is  often  seen  in  carvings. 

The  Bhotan  Pine  (Pinus  excelsa)  of  the  Himalayas  closely  re- 
sembles the  White  Pine  tree  in  size  and  habit,  and  yields  a  wood 
which  is  very  similar  to  White  Pine. 

The  Lodgepole  Pine  (Pinus  murrayana)  also  called  the  Tamarack, 
Tamarack  Pine,  Murray  Pine,  Prickly  Spruce,  Black  Spruce,  and  White 
Spruce,  grows  from  Alaska  to  California  and  New  Mexico.  Trees  often 
grow  at  altitudes  of  six  to  eleven  thousand  feet.  The  remarkably  tall, 
slender  trunks  can  be  made  into  ties,  posts,  and  poles.  The  light, 
straight-grained  woods  are  hard  to  season,  but  easy  to  work.  Trees 
are  sensitive  to  fires,  but  these  fires  do  not  normally  kill  the  seeds  (see 
also  Erickson,  "Forestry  and  Irrigation,"  p.  503,  1904;  "The  Lodgepole 
Pine,"  Ziegler,  U.  S.  Forest  Service  Circular  No.  126;  "Utilization  and 
Management  of  Lodgepole  Pine  in  the  Rocky  Mountains,"  Mason. 
United  States  Department  of  Agriculture,  Bulletin  No.  234,  1915; 
etc.). 

The  Spruce  Pine  (Pinus  glabra)  is  the  least  common  of  the  lower 
southern  states  pines.  It  seldom  forms  pure  forests  and  is  of  relatively 
small  commercial  importance.  The  wood  resembles  that  of  the  Lob- 
lolly Pine.  The  name  Spruce  Pine  is  popularly  applied  to  trees  of  ten 
other  American  species  (Sudworth).  Two  of  these  are  not  pines. 

The  Pond  Pine  (Pinus  serotina). — This  is  the  Marsh  Pine  of  the  woods- 
man. The  wood  is  seldom  distinguished  at  the  mills  where  it  furnishes 
much  of  the  lumber  known  as  North  Carolina  Pine.  Pond  pine  trees 
grow  along  the  Atlantic  coast  from  Albermarle  Sound  south  to  Florida. 
The  six-inch  or  eight-inch  leaves  are  in  tufts  of  three.  The  cones  some- 
times remain  on  the  trees  for  several  years.  The  trees  are  now  bled  for 
turpentine.  The  Pond  Pine  is  also  known  as  the  Meadow,  Loblolly, 
Spruce,  Bastard  and  Bull  Pine  (see  also  Roth,  U.  S.  Forestry  Bulletin 
No.  13). 

The  Monterey  Pine  (Pinus  radiata). — This  tree  grows  best  near 
Monterey,  California.  It  is  often  one  hundred  feet  high  and  is  sym- 
metrical or  distorted,  according  to  its  exposure.  Monterey  pine  trees 
are  widely  transplanted  for  landscape  effects,  and  the  trunks  are  occa- 
sionally cut  into  lumber. 

The  Digger,  Grayleaf,  Gray  or  Sabine  Pine  (Pinus  sabiniana)  of 
western  California  affords  a  poor  and  seldom-used  wood.  The  nuts 
were  prized  by  Digger  Indians,  whence  the  name.  The  tree  forms  are 
unusual.  The  trunks  are  divided  and  the  sparse,  grayish  foliage  is  more 
or  less  concentrated  near  the  ends  of  the  branches.  The  Digger  Pine 
yields  a  turpentine  (abietene)  that  is  used  in  medicine. 

The  Scrub  Pine  or  Jack  Pine  (Pinus  divaricata)  of  the  north-central 
and  Atlantic  states,  yields  a  wood  that  is  sometimes  classed  among  the 


CONIFEROUS  TRUNKS  AND  WOODS  61 

lighter  Hard  Pines  and  that  is  used  for  ties  and  fuel.     The  species  is 
hardy  in  some  semi-arid  regions  where  other  pines  will  not  grow. 

The  Scrub  Pine  or  Jersey  Pine  (Pinus  virginiana)  grows  from  Staten 
Island,  southward  and  westward  into  Alabama  and  Tennessee.  The 
inferior  wood  is  used  for  fuel,  water-pipes,  and  coarse  lumber. l 


lSee  also  "Scrub  Pine"  (Pinus  virginiana),  (United  States  Forest  Service, 
Bulletin  No.  94,  19 ID. 


KAURI  PINE 

Dammara 

The  Kauri  Pine  grows  in  New  Zealand  and  yields  a  strong 
light,  durable,  and  elastic  wood.  The  tough,  leather-like  leaves 
suggest  those  of  the  Box. 

The  reputation  of  the  species  depends  principally  upon  a  resin 
which  is  much  used  in  the  manufacture  of  high-grade  varnishes. 
This  resin  unites  with  linseed  oil  more  perfectly  and  at  lower 
temperatures,  than  most  other  varnish  resins,  and  has  sold  for 
more  than  one  thousand  dollars  a  ton.  The  best  Kauri,  known 
as  "  fossil  resin,"  is  obtained  by  digging  over  areas  from  which 
the  trees  have  disappeared.  These  deposits  exist  a  few  feet 
below  the  surface  and  yield  pieces  that  commonly  vary  in  size 
from  small  pebbles  to  lumps  as  large  as  eggs.  One  exceptional 
mass,  weighing  two  hundred  and  twenty  pounds,  has  been 
reported.1  There  are  also  "semi-fossil"  and  " fresh-product" 
resins.  The  fresh  exudations  from  Kauri  Pine  trees  resemble  the 
product  known  as  Venice  turpentine. 

Varnish  resins  may  be  roughly  divided  according  to  the  manner  in 
which  they  unite  with  oil  and  with  spirit.  In  the  first  case,  oil  becomes 
part  of  the  whole,  whereas,  in  the  second  case,  spirits  simply  dissolve 
the  ingredients  and  then  evaporate  from  them.  As  noted,  Kauri  resin 
is  one  of  the  best  of  the  oil-varnish  resins,  and,  in  a  similar  way,  shellac 
is  among  the  valuable  spirit- varnish  resins. 

Gums  and  resins  should  be  distinguished  from  one  another.  A  true 
gum  usually  dissolves  in  water,  while  a  true  resin  usually  yields  to  oil 
or  spirit.  A  solution  of  gum  and  water  forms  a  mucilage.  The  name 
gum  is  often  applied  for  convenience  to  substances  that  are  actually 
resins. 

1  "Notes  on  Fossil  Resins,"  R.  Ingham  Clark  (published  by  C.  Letts  & 
Company,  London). 


62 


CONIFEROUS  TRUNKS  AND  WOODS  63 

.  Dammara  australis  Lambert 

Agathis  australis  Salisbury 

OMENCLATURE. 

Kauri  Pine  (local  and  general).  Cowdie  Pine   (New  Zealand  and 

many  localities). 

LOCALITIES. 
New  Zealand. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  feet  in  height;  three  to  four  feet  in  diameter; 
occasional  specimens  much  larger;  a  tall,  handsome  tree;  the  willow- 
like  leaves  are  from  two  to  three  and  one-half  inches  long,  and  from 
one-half  to  three-fourths  of  an  inch  in  breadth;  the  cones  are  about 
two  and  one-half  inches  in  diameter;  the  resin  is  characteristic. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  straw-colored ;  fine,  straight  grain,  with  silky  luster  suggesting 
Satinwood;  "mottled  Kauri"  is  separated  and  used  for  cabinet  work. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Moderately  hard,  light,  elastic,  and  strong;  it  seasons  well,  works  readily, 
and  receives  a  high  polish;  it  is  quite  free  from  knots;  it  stands  well, 
wears  evenly,  and  has  an  agreeable  odor. 

REPRESENTATIVE  USES  OF  WOOD. 
Carpentry  and  masts. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
33  (Laslett)  varies  with  locality. 

MODULUS  OF  ELASTICITY. 
1,810,000  (Laslett). 

MODULUS  OF  RUPTURE. 

REMARKS. 

The  species  is  widely  known  by  its  resin.  The  most  valuable  forest 
tree  of  New  Zealand. 


SPRUCE 

Picea 

Spruce  trees  form  forests  in  North  America  and  in  Europe. 
The  Norway  Spruce,  or  " White  Fir"  (Picea  excelsa),  is  the  prin- 
cipal species  in  Europe,  while  the  Black  Spruce  (Picea  nigra),  the 
White  Spruce  (Picea  alba),  and  the  Red  Spruce  (Picea  rubens) 
are  notable  in  some  parts  of  the  East  in  the  United  States.  The 
White  Spruce  (Picea  engelmanni)  is  an  important  species  in  the 
West.  In  North  America  spruce  trees  prefer  northern  localities 
where  there  are  short  summers  and  long  winters. 

The  eastern  American  species  yield  soft,  clean,  light,  close- 
grained  woods  that  are  much  valued  in  constructions.  The 
Western  Spruce  yields  a  valuable  wood,  but  this  is  less  familiar 
because  of  its  remoteness  from  the  eastern  markets.  Spruce 
resembles  and  forms  one  of  the  best  eastern  substitutes  for  White 
Pine.  It  is  also  valued  for  paper  pulp. 

The  eastern  product  is  divided  according  to  appearance,  and 
irrespective  of  species,  into  "  White  Spruce"  and  "Black  Spruce." 
The  pieces  that  have  wide  annual  layers  are  usually  classed  as 
White  Spruce,  while  those  that  have  narrow  layers  are  classed  as 
Black  Spruce.  Spruce  woods  and  Fir  woods  are  often  confused 
with  one  another,  and  there  are  so-called  spruce  trees,  as  "Doug- 
las Spruce"  and  "Kauri  Spruce,"  that  are  not  true  spruces. 
European  Spruce  is  sometimes  known  locally  as  "White  Deal." 

The  insect  and  fungus  enemies  of  spruce  trees  have  received 
much  attention.1  The  largest  and  best  trees  seem  most  liable 
to  attack.  Hopkins  states  that  the  spruce-destroying  beetle 
(Dendroctonus  piceaperda)  is  accountable  for  much  of  the  damage 
done  in  the  eastern  states.  This  beetle  gains  entrance  to  the 
tree  through  crevices  in  the  bark,  and  then  cuts  grooves  on  the 
surface  of  the  sensitive  outer  sap  wood.  The  resins  that  collect 
in  these  grooves  or  tunnels  are  ejected  and  form  what  are  known 
as  "pitch  tubes."  The  presence  of  pitch  tubes  and  particles  of 
wood  on  the  ground  at  the  base  of  a  tree  is  evidence  that  the 
tree  has  been  attacked.  An  intimate  connection  exists  between 
the  attacks  of  these  and  other  insects,  and  those  of  fungi.  The 

64 


CONIFEROUS  TRUNKS  AND  TREES 


65 


latter  may  lodge  in  and  infect  wounds  caused  by  the  former.  It 
should  be  noted  that  wood  may  remain  sound  for  sometime 
after  the  physical  death  of  the  tree,  and  that  such  wood  can  be 
used  for  lumber  and  for  paper  pulp. 

"  Windfalls"  may  result  from  insects,  fungi,  age,  fire,  and  tornadoes, 
or  from  a  combination  of  these  agencies.  In  windfalls,  trees  are  piled 
promiscuously  upon  one  another  like  giant  jackstraws.  Trunks  and 
limbs  intermingle  and  later  the  mass  is  often  penetrated  by  wiry,  second- 
growth  saplings.  Passage  through  such  a  district  is  made  by  cautiously 
walking  backward  and  forward,  up  and  down  over  trunks  and  limbs. 
It  is  sometimes  impossible  to  proceed  for  more  than  two  or  three  miles 


daily  in  a  straight  line  through  a  windfall, 
also  sometimes  used.2 


The  term  "blowdown"  is 


Spruce  trees  have  single,  short,  sharp-pointed  leaves  which  are 
keeled  above  and  below  and  which  therefore  appear  four-sided. 
Spruce  cones  hang  downward.  Spruce  trees  may  be  distin- 
guished from  Pines,  Firs,  and  Hemlocks,  by  remembering  that 
pine  leaves  are  longer  and  grow  in  clusters,  that  hemlock  leaves 
are  flat,  blunt,  and  two-ranked,  and  that  the  cones  of  the  Fir 
tree  point  upward. 


Names 

Arrangement  of  leaves 

Shape  of  leaves 

Cones 

Pine  (Pinus)  .  .  . 

In  tufts  or  clusters. 

Comparatively  long. 

Spruce  (Picea). 

Single,    scattered, 

Short,     sharp     ends, 

Hang    down, 

point   in    all   direc- 

keeled above  and  be- 

1  to  6  inches 

tions. 

low.     Somewhat 

long. 

four-sided. 

Fir  (Abies)  

Single,  scattered,  ap- 

Short,    blunt     ends, 

Stand    erect, 

pear  somewhat  as  in 

flat. 

2  to  4  inches 

tiwo  ranks. 

long. 

Hemlock 

Single,  scattered,  ap- 

Short,    blunt     ends, 

Hang    down, 

(Tsuga). 

pear  as  in  two  ranks. 

flat. 

%  to  1  inch 

long. 

1  "Insect  Enemies  of  Spruce  in  the  Northeast"  and  "Insect  Enemies  of 
the  Forest  of  the  Northwest,"  Hopkins  (United  States  Division  Entomology, 
Bulletins  No.  28  and  No.  21);  also  "Diseases  New  England  Conifers,"  von 
Schrenk   (United  States   Division  Vegetable   Physiology  and  Pathology, 
Bulletin  No.  25. 

2  See  "Transactions  American  Institute  Mining  Engineers,"   1899;  see 
also  "Third  Annual  Report  Pennsylvania  Department  Agriculture." 


66  ORGANIC  STRUCTURAL  MATERIALS 

Picea  nigra  Link 

Black  Spruce.          D.          y  .        ,,.„ 
Picea  manana  Mill 

NOMENCLATURE  (Sudworth). 
Spruce  (Vt.),  Yew  Pine,  Spruce         White  Spruce  (W.  Va.). 

Pine  (W.  Va.).  He  Balsam  (Del.,  N.  C.). 

Double  Spruce  (Me.,  Vt.,  Minn.).         Water  Spruce  (Me.). 
Blue  Spruce  (Wis.). 

LOCALITIES. 

Labrador  and  Alaska,  southward  to  New  York,  Pennsylvania,  Wisconsin, 
and  Saskatchewan. 

FEATURES  OF  TREE. 

Forty  to  eighty  feet  in  height;  one  to  two  feet  in  diameter;  conical  shape, 
with  straight  trunk;  four-sided  leaves  are  somewhat  narrowed  toward 
the  tips;  the  leaves  are  from  three-eighths  of  an  inch  to  five-eighths  of 
an  inch  in  length;  they  are  lighter  on  the  upper  surfaces  than  on  the 
lower;  cones  remain  for  several  years,  being  thus  distinct  from  those 
of  the  White  Spruce  (Picea  alba). 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish,  nearly  white;  sapwood  lighter;  straight  grain;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  soft,  not  strong,  elastic,  and  resonant;  not  durable  when  exposed. 

REPRESENTATIVE  USES  OF  WOOD. 

Lumber,  flooring,  carpentry,  ship-building,  piles,  posts,  railway  ties, 
paddles,  oars,  "sounding-boards,"  and  paper-pulp. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,560,000. 
MODULUS  OF  RUPTURE. 

10,600. 
REMARKS. 

A  substitute  for  Soft  Pine.  See  also  "Black  Spruce,  Picea  mariana 
(Mill.)"  (United  States  Forest  Service,  Silvical  Leaflet  No.  28,  1908). 


The  Red  Spruce  (Picea  rubens)  is  one  of  the  principal  lumber  trees  of 
northern  New  England.  This  tree,  which  is  much  like  the  Black  Spruce, 
is  from  fifty  to  eighty  feet  in  height,  and  from  two  to  three  feet  in  diameter. 
Large  quantities  of  its  light,  close-grained,  reddish,  satiny  wood  are  cut  into 
lumber  or  used  in  the  manufacture  of  paper-pulp. 


CONIFEROUS  TRUNKS  AND  WOODS  67 

White  Spruce.     Picea  alba  Link 

Picea  canadensis  Mill 

NOMENCLATURE  (Sudworth). 

Single  Spruce  (Me.,  Vt.,  Minn.).         Skunk  Spruce  (Wis.,  New  Eng  ) 
Bog  Spruce,  Cat  Spruce  (New  Eng.).    Spruce,  Double  Spruce  (Vt.). 

Pine  (Hudson  Bay). 

LOCALITIES. 

Northern  United  States,  Canada  to  Labrador  and  Alaska. 

FEATURES  OF  TREE. 

Fifty  to  one  hundred  feet  in  height;  one  to  two  feet  in  diameter;  occa- 
sionally larger;  compact,  symmetrical,  conical  shape;  foliage  lighter 
than  Black  Spruce;  cones  fall  sooner  than  those  of  Black  Spruce; 
whitish  resin. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  yellow;  sapwood  similar;  straight-grained;  numerous 
prominent  medullary  rays;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong  (similar  to  those  of  Black  Spruce  (Picea  nigra). 

REPRESENTATIVE  USES  OF  WOOD. 

Lumber,  flooring,  carpentry,  etc.  (similar    to    those    of    Black    Spruce 
(Picea  nigra). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

25. 
MODULUS  OF  ELASTICITY. 

1,450,000. 
MODULUS  OF  RUPTURE. 

10,600. 
REMARKS. 

Notable  as  resident  of  high  latitudes.  One  of  the  chief  trees  of  the 
Arctic  forests.  The  wood,  used  similarly  to  Black  Spruce,  is  substi- 
tuted for  White  Pine. 


It  is  often  difficult  to  distinguish  between  Black  Spruce  trees  and  those  of 
the  White  Spruce.  On  the  whole,  the  foliage  of  the  former  is  darker;  there 
are  also  differences  in  the  shapes  and  in  the  persistence  of  the  cones.  The 
names  "  Double  Spruce"  and  "Single  Spruce"  are  without  botanical  founda- 
tion. Woods  obtained  from  these  two  trees  exhibit  similar  qualities  and 
are  not  separated  by  lumbermen. 


68  ORGANIC  STRUCTURAL  MATERIALS 

White  Spruce.  Picea  engelmanni  Engelm 

NOMENCLATURE  (Sudworth). 

White  Spruce  (Ore.,  Col.,  Utah,         White     Pine     (Idaho),     Mountain 

Idaho).  Spruce  (Mont.). 

Balsam,      Engelmann's     Spruce 

(Utah). 

LOCALITIES. 

British  Columbia  to  Oregon,  eastward  to  Alberta,  and  south  through  the 
Rocky  Mountain  region  to  northern  New  Mexico  and  Arizona. 

FEATURES  OF  TREE. 

Frequently  seventy-five  to  one  hundred  feet  in  height;  sometimes  one 
hundred  and  fifty  feet  in  height;  two  to  three  feet  in  diameter;  sometimes 
a  low  shrub;  the  straight,  slender  leaves  are  from  three-fourths  of  an 
inch  to  one  and  one-fourth  inches  in  length;  they  are  flexible,  with 
sharp,  thick  tips,  and  they  spread  in  all  directions;  the  elliptical  cones 
are  from  one  and  one-half  inches  to  two  and  one-half  inches  long;  the 
scales  are  toothed  at  the  apex.1 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  pale  reddish  yellow;  sapwood  similar;  close,  straight  grain; 
compact  structure;  conspicuous  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Lumber,  charcoal  and  fuel;  bark  rich  in  tannin  is  sometimes  used  for 
tanning. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

21. 
MODULUS  OF  ELASTICITY. 

1,140,000. 
MODULUS  OF  RUPTURE. 

8,100. 
REMARKS. 

Notable  as  a  resident  of  high  altitudes,  extensive  forests  occurring  at 
eight  to  ten  thousand  feet  above  sea-level.  A  valuable  tree  of  the  cen- 
tral and  southern  Rocky  Mountain  regions. 

^'Engelmann  Spruce  in  the  Rocky  Mountain,"  Hodson  and  Foster 
(United  States  Forest  Service,  Circular  No.  170);  "Engelmanns  Spruce" 
Pinchot  (United  States  Forest  Service,  Silvical  Leaflet  No.  3,  1907). 


CONIFEROUS  TRUNKS  AND  WOODS  69 

Sitka  Spruce.  Picea  sitchensis  Trautv.  and  Mayer 

NOMENCLATURE  (Sudworth). 

Sitka  Spruce  (local  and  common         Menzies  Spruce, 
name).  Western  Spruce. 

Tideland    Spruce    (Cal.,    Oreg.,         Great  Tideland  Spruce. 
Wash.). 

LOCALITIES. 

Pacific  Coast  region,  Alaska  to  central  California;  extends  inland  about 
fifty  miles;  prefers  low  elevations. 

FEATURES  OP  TREE. 

One  hundred  and  fifty  or  more  feet  in  height;  three  feet  or  more  in  di- 
ameter; the  stiff,  straight,  flat  leaves,  which  are  from  five-eighths  of  an 
inch  to  three-fourths  of  an  inch  in  length,  radiate  in  all  directions;  the 
oval  or  cylindrical  cones  are  from  three  to  four  inches  in  length;  the 
bark  is  scaly  and  of  a  reddish-brown  color.1 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  reddish  brown;  sapwood  nearly  white;  coarse-grained; 
satiny. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Construction,  interior  finish,  fencing,  boat-building,  and  cooperage. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

2,626. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 

10,400. 
REMARKS. 
A  giant  among  the  spruces.     Forms  an  extensive  coast-belt  forest. 


1  "Sitka  Spruce,"  Pinchot  (United  States  Forest  Service,  Silvical  Leaflet 
No.  6,  1907). 


DOUGLAS   SPRUCE,  DOUGLAS  FIR,  OREGON  PINE 

Pseudotsuga. 

These  trees  form  almost  pure  forests  in  Washington  and  Ore- 
gon. They  grow  sparingly  in  Mexico,  Texas,  and  at  high  alti- 
tudes in  Colorado.  Transplanted  specimens  have  survived  in 
New  York.  It  should  be  noted  that  the  Douglas  Spruce  is 
neither  Spruce,  Fir,  or  Pine.  The  generic  name  is  from  pseudo 
or  "false,"  and  tsuga  or  " Hemlock,"  and  the  tree  may  be  regarded 
as  in  the  nature  of  a  bastard  Hemlock.  The  species  has  also 
been  classed  as  Pinus  taxifolia  and  Abies  taxifolia.1 

The  durable,  strong,  light  red,  or  yellow  wood,  which  resembles 
larch  or  true  hard  pine  is  used  in  place  of  hard  pine  on  the 
Pacific  Coast.  It  is  one  of  the  general  utility  woods  of  that  coast. 
The  trees  are  among  the  greatest  known  to  man.  Individuals 
have  reached  heights  of  three  hundred  and  fifty  feet,2  and  diame- 
ters of  twelve  and  even  fifteen  feet.  Logs  that  yield  timbers 
two  feet  square  and  one  hundred  feet  long  are  not  uncommon. 
Single  trees  have  been  cut  that  scaled  sixty  thousand  feet  board 
measure.  The  Douglas  Spruce  grows  rapidly.  It  is  hardy,  and, 
like  the  redwoods,  is  likely  to  resist  commercial  extinction. 

Red  and  Yellow  varieties  of  Douglas  Spruce  wood  are  recog- 
nized by  lumbermen.  The  former  woods  come  from  younger 
trees,  and  are  coarser  and  less  valuable  than  the  latter  kinds 
which  come  from  the  older  trees.  The  wood  is  also  marketed 
under  the  commercial  names  of  Oregon  Pine,  Hard  Pine,  Pacific 
Pine,  Red  Spruce,  Red  Fir,  Yellow  Fir,  etc.  The  genus  includes 
one  other  species,  the  much  less  important  Big  Cone  Spruce 
(Pseudotsuga  macrocarpa)  of  California,  which  yields  an  inferior 
wood. 

1  Some  difficulties  associated  with  the  classification   of  this  tree  are 
enumerated  on  pages  23  and  24  of  Sudworth's  Check  List. 

2  The  tallest  specimen  recorded  was  three  hundred  and  eighty  feet  high. 
See  also  "Growth  and  Management  of  Douglas  Fir  in  Pacific  Northwest," 

Munger  (United  States  Forest  Service  Circular  No.  175,  p.  23);  "Properties 
and  Uses  of  Douglas  Fir,"  Cline  and  Knap  (United  States  Forest  Service 
Bulletin  No.  88);  "Douglas  Fir,"  Frothingham  (United  States  Forest 
Service,  Circular  No.  150,  1909);  "Douglas  Fir,"  Detwiler  (American 
Forestry,  February,  1916). 

70 


CONIFEROUS  TRUNKS  AND  WOODS  71 

Pseudotsuga  mucronata  Sudw. 

Douglas  Spruce,  Douglas  Fir.        Pseudotsuga  taxi/olio,  Lam 

Pseudotsuga  Douglasii  Can 

NOMENCLATURE  (Sudworth). 

Oregon  Pine  (Cal.,  Wash.,  Ore.)  Douglas-tree,  Cork-barked  Douglas 

Red  Fir,  Yellow  Fir  (Ore.,  Wash.,  Spruce.     (Occasional) 

Idaho,  Utah,  Mont.,  Col.).  Spruce,  Fir  (Mont.) 

Red  Pine  (Utah,  Idaho,  Col.).  Puget  Sound  Pine  (Wash.). 

LOCALITIES. 

Pacific  Coast  region,  Mexico  to  British  Columbia;  best  in  Western  Ore- 
gon and  Washington. 

FEATURES  OF  TREE. 

One  hundred  and  seventy-five  to  sometimes  three  hundred  feet  in  height ; 
three  to  five  and  sometimes  ten  feet  in  diameter;  older  bark  rough-gray, 
often  looking  as  though  braided.  One  of  the  world's  greatest  trees. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  red  to  yellow;  scant  sapwood  nearly  white;  comparatively 
free  from  resins;  pronounced  variable  rings  (four  to  forty  per  inch). 

STRUCTURAL  QUALITIES  OF  WOOD. 

Variable,  usually  hard,  and  strong;  rather  difficult  to  work,  durable, 
splits  easily,  can  be  obtained  in  large  pieces.  l 

REPRESENTATIVE  USES  OF  WOOD. 

Heavy  constructions,  dimension-timbers,  lumber,  railway  ties,  paving 
blocks,  wood-stave  pipes,  posts,  poles,  piles,  masts,  and  fuel.  The  wood 
is  used  much  as  hard  pine  is  used. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
32  (United  States  Forestry  Division).2 
36  (Average  of  20  tests  by  Soule).3 
32. 

MODULUS  OF  ELASTICITY. 

1,680,000  (average  of  41  tests  by  United  States  Forestry  Division).2 

1,862,000  (average  of  21  tests  by  Soule).3 

1,824,000. 

MODULUS  OF  RUPTURE. 

7,900  (average  of  41  tests  by  United  States  Forestry  Division).2 
9,334  (average  of  21  tests  by  Soule).3 
12,500. 

REMARKS. 

1  See  also"  Properties  and  Uses  of  Douglas  Fir:  Pt.  1,  Mechanical  Properties; 
Pt.  2,  Commercial  Uses"  (United  States  Forest  Service,  Bulletin  No.  88, 
1911). 

2  See  p.  33. 

3  Professor  Frank  Soule",  University  of  California,  Trans.  Am.  Inst.  M.  E., 
Vol.  XXIX,  p.  552. 


FIR 

A  hies 

The  Silver  Fir  (Abies  grandis),  the  Red  Fir  (Abies  magnified], 
and  the  Noble  Fir  (Abies  nobilis),  are  valued  west  of  the  Rocky 
Mountains,  while  the  Balsam  Fir  (Abies  balsamea)  is  of  some  com- 
mercial importance  in  the  East. 

Some  of  the  Fir  trees  in  the  Western  States  are  so  large  as  to 
call  for  the  special  methods  that  are  used  to  fell  the  giant  .speci- 
mens of  other  species.  In  such  cases  platforms  are  erected,  far 
enough  up  from  the  ground,  so  that  axemen,  standing  upon  them, 
can"  cut  through  above  the  hollow  or  decayed  parts  that  are 
common  near  the  surface  of  the  ground.  It  is  also  arranged  so 
that  the  trees,  as  they  fall,  shall  strike  the  ground  more  or  less 
uniformly  along  their  sides  and  thus  diminish  the  danger  from 
splintering  or  breaking,  which  is  associated  with  the  impact  of 
such  large  trunks.1 

Fir  and  Spruce  resemble  one  another  in  appearance  and  struc- 
tural qualit'es  and  are  often  used  in  place  of  one  another  in  the 
United  States.  Fir,  Spruce,  and  Pine  are  often  confused  with 
one  another  in  Europe. 

Fir  trees  have  flat,  scattered,  evergreen  leaves  and  erect  cones. 
The  Balsam  Fir  may  be  distinguished  by  blisters,  abundantly 
supplied  in  the  bark  of  all  but  the  oldest  trunks,  which  contain  a 
clear,  liquid  resin  known  as  Canada  Balsam. 


1  Descriptions  of  special  methods  employed  in  harvesting  Douglas  Spruce, 
Redwoods,  Giant  Cedars,  and  other  Western  species  are  as  follows:  Engi- 
neering Magazine,  Bishop  (Vol.  XIII,  p.  70) ;  National  Geographic  Magazine, 
Gannett  (Vol.  X,  No.  5,  May,  1899). 

72 


CONIFEROUS  TRUNKS  AND  WOODS  73 

Balsam  Fir,  Common  Balsam  Fir.  Abies  balsamea  (L.)  Mill. 

NOMENCLATURE  (Sud worth). 

Balsam  (Vt.,  N.  H.,  N.  Y.).  Blister  pine,  Fir  Pine  (W.  Va.). 

Fir  Tree  (Vt.).  Single  Spruce,  Silver  Pine  (Hudson 

Balm  of  Gilead  (Del.).  Bay). 

Canada  Balsam  (N.  C.). 

Balm  of  Gilead  Fir.(N.  Y.,  Pa.). 

LOCALITIES. 

Labrador,  southward  through  the  mountains,  and  westward  to  Minnesota. 

FEATURES  OF  TREE. 

Fifty  to  seventy  feet  in  height;  one  to  two  feet  in  diameter;  sometimes  a 
low  shrub;  blisters  in  smooth  bark  contain  thick  balsam;  erect  cones. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  white  to  brownish;  sap  wood  lighter;  coarse-grained;  compact 
structure;  satiny. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  light,  not  durable  or  strong,  resinous,  and  easily  split. 

REPRESENTATIVE  USES  OF  WOOD. 
Occasionally  used  as  inferior  lumber. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

23. 
MODULUS  OF  ELASTICITY. 

1,160,000. 
MODULUS  OF  RUPTURE. 

7,300. 
REMARKS. 

These  trees  grow  naturally  over  Northern  pine  lands,  and  yield  wood 
which  is  commonly  sold  with  Spruce  and  Pine.  Of  all  the  native  coni- 
fers this  is  one  of  the  most  difficult  trees  to  cultivate.  The  thick 
fluid-resin,  or  balsam,  known  as  Canada  Balsam,  is  used  in  medicine. 
It  should  be  noted  that  the  Poplar  (Populus  balsamifera)  is  also  called 
Balm  of  Gilead.  See  also  "Balsam  Fir,"  Zon  (United  States  Depart- 
ment of  Agriculture  Bulletin  No.  55). 


74  ORGANIC  STRUCTURAL  MATERIALS 

Great  Silver  Fir,  White  Fir.  Abies  grandis  LindL 

NOMENCLATURE  (Sudworth). 

Silver  Fir  (Mont.,  Idaho).  Yellow  Fir  (Mont.,  Idaho) 

Oregon  White  Fir,  Western  White       Lowland  Fir. 
Fir  (Cal.). 

LOCALITIES. 

Vancouver  region,  northwestern  United  States;  best  in  western  Washing- 
ton and  Oregon. 

FEATURES  OP  TREE. 

Two  hundred  to  sometimes  three  hundred  feet  in  height;  two  to  five  feet 
in  diameter;  leaves  deep  green  above,  silvery  below,  usually  curved; 
a  handsome  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown;  sapwood  lighter;  coarse-grained;  compact 
structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 
Lumber,  interior  finish,  packing-cases,  and  cooperage. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

22. 
MODULUS  OF  ELASTICITY. 

1,360,000. 
MODULUS  OF  RUPTURE. 

7,000. 
REMARKS. 

These  trees  form  an  important  part  of  local  mountain  forests  and  furnish 
much  lumber  locally.  They  grow  best  on  rich  bottom  lands,  but  are 
also  found  at  altitudes  of  five  thousand  and  even  six  thousand  feet. 
The  balsam  contained  in  blisters  in  the  young  bark  is  used  in  medicine. 
The  specific  name  grandis  was  given  because  of  the  great  size  to  which 
some  trees  of  this  species  grow.  See  also  " Lowland  Fir,"  Pinchot 
(United  States  Forest  Service,  Silvical  Leaflet  No.  5,  1907). 


CONIFEROUS  TRUNKS  AND  WOODS  75 

Red  Fir.  Abies  magnified  Murr 

NOMENCLATURE  (Sudworth). 

California    Red    Fir,    California         Magnificent  Fir,  Golden  Fir  (Cal.). 
Red-bark  Fir  (Cal.). 

LOCALITIES. 

Mountains  of  northern  California,  Oregon,  and  Nevada. 

FEATURES  OF  TREE. 

One  hundred  to  two  hundred  and  fifty  feet  in  height;  six  to  ten  feet  in 
diameter;  large,  erect  cones;  beautiful  form. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish;  sapwood  distinguishable;  rather  close-grained;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light  and  soft;  not  strong,  durable  when  exposed,  liable  to  injury  in 
seasoning. 

REPRESENTATIVE  USES  OF  WOOD. 
Construction,  sills,  lumber,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

29. 
MODULUS  OF  ELASTICITY. 

940,000. 
MODULUS  OF  RUPTURE. 

9,900. 
REMARKS. 

The  specific  name  refers  to  the  appearance  and  size  of  the  tree. 


76  ORGANIC  STRUCTURAL  MATERIALS 

White  Fir,  Balsam  Fir.  Abies  concolor  Lindl.  and  Gord. 

NOMENCLATURE  (Sudworth).  White  Balsam  (Utah). 

Silver  Fir,  Balsam  (Cal.).  Balsam-tree  (Idaho). 

California  White  Fir  (Cal.).  Colorado  White  Fir,  Concolor  White 

Black  Gum,  Bastard  Pine  (Utah).  Fir. 

LOCALITIES. 

Rocky  Mountains  and  coast  ranges;  high  elevations. 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  and  fifty  feet  in  height;  three  to  five  feet  in 
diameter;  the  blisters  in  the  bark  are  filled  with  clear  pitch.1 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown  to  nearly  white;  sapwood  same  or  darker;  coarse- 
grained; compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong;  without  odor. 

REPRESENTATIVE  USES  OF  WOOD. 

Butter-tubs,  packing-boxes,  and  lumber. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

22. 
MODULUS  OF  ELASTICITY. 

1,290,000. 
MODULUS  OF  RUPTURE. 

9,900. 
REMARKS. 

Not  always  distinguished  from  the  species  Abies  lowiana. 


*"  White  Fir,"  Pinchot  (United  States  Forest  Service,  Silvical  Leaflet 
No.  4,  1907). 


CONIFEROUS  TRUNKS  AND  WOODS  77 

Red  Fir,  Noble  Fir.  Abies  nobilis  LindL 

NOMENCLATURE  (Sudworth). 

Noble  Silver  Fir,  Noble  Red  Fir.         Bigtree,     Feather-cone,     Red     Fir 
Larch  (Oreg.).  (Cal.). 

LOCALITIES. 

Northwestern  United  States;  cultivated  in  the  East. 

FEATURES  OF  TREE. 

One  to  two  hundred  feet  in  height;  six  to  nine  feet  in  diameter;  the 
leaves  are  curved;  a  large,  beautiful  tree.1 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish-brown;  sap  wood  darker;  rather  close-grained;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  hard,  strong,  and  elastic. 

REPRESENTATIVE  USES  OF  WOOD. 
Fitted  for  house-trimmings. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,800,000. 
MODULUS  OF  RUPTURE. 

22,200. 
REMARKS. 
Red  Fir  trees  grow  at  elevations  of  three  thousand  and  four  thousand  feet. 

With  other  fir  trees,  they  form  extensive  forests.     The  wood  is  often 

sold  as  Larch. 


1  Peters  (Forestry  and  Irrigation,  Vol.  VIII,  No.  9,  Sept.,  1902,  pp.  362, 
366);  "Noble  Fir,"  Pinchot  (United  States  Forest  Service,  Silvical  Leaflet 
No.  7,  1907). 


HEMLOCK 

Tsuga 

Hemlock  trees  grow  in  some  of  the  central  and  northern  states 
east  of  the  Rocky  Mountains,  and  also  on  the  Pacific  Coast  as 
far  north  as  Alaska.  They  sometimes  mingle  with  other  trees, 
and  sometimes  form  pure  forests  by  themselves. 

The  wood  of  the  Eastern  Hemlock  (Tsuga  canadensis)  is 
coarse,  brittle,  often  cross-grained,  usually  hard  to  work,  liable 
to  warp  and  splinter,  and  perishable  when  exposed.  It  cannot 
be  relied  upon  to  sustain  shocks.  It  holds  nails  firmly  and  is 
used  for  coarse  lumber,  dimension  pieces,  paper  pulp,  and  cheap 
finish.  Some  of  the  prejudice  that  exists  against  hemlock  is  due 
to  the  fact  that  it  was  formerly  compared  with  white  pine,  spruce 
and  fir.  The  supplies  of  these  better  woods  have  since  diminished 
and  the  value  of  hemlock  has  increased  correspondingly. 

The  wood  of  the  Western  Hemlock  (Tsuga  heterophylla) ,  which 
is  much  better  and  stronger  than  Eastern  Hemlock,  has  suffered 
because  of  the  reputation  of  the  Eastern  Hemlock.  Western 
Hemlock  has  a  pronounced  odor  which  makes  it  disliked  by 
insects  and  rodents.  For  this  reason  it  is  sometimes  used  to 
line  grain-bins.  The  wood  is  also  used  for  flooring,  mill  frames, 
boxes,  and  paper  pulp.  It  is  seldom  sold  under  its  true  name, 
but  names  such  as  Alaska  Pine  and  Red  Fir  are  preferred.  Black 
streaks  sometimes  exist  with  the  grain.  These  are  more  or  less 
evident  and  the  pieces  in  which  the  streaks  exist  are  often  sold 
as  Black  Hemlock.  The  True  Black  or  Alpine  Hemlock  (Tsuga 
mertensiana)  often  grows  at  high  altitudes  or  in  the  far  North  and 
is  not  yet  widely  available.1 

Hemlock  trees  have  flat,  blunt,  evergreen  leaves,  the  under- 
sides of  which  appear  to  be  whitened.  The  leaves  are  arranged 
in  two  ranks.  The  inner  bark  is  red. 

The  Western  Hemlock  (Tsuga  heterophylla}  grows  from  Alaska  to  Cali- 
fornia and  attains  a  height  of  one  hundred  and  eighty  feet  and  a  diameter 
of  nine  feet.  It  is  said  to  afford  heavier  and  better  wood  than  that  obtained 
from  the  common  Hemlock.  The  Western  Hemlock  is  known  by  the  fol- 
lowing names  (Sudworth) :  Western  Hemlock,  Hemlock  Spruce  (Cal.);  Hem- 

78 


CONIFEROUS  TRUNKS  AND  WOODS  79 

lock  (Oreg.,  Idaho,  Wash.);  Alaska  Pine  (Northwestern  Lumberman); 
Prince  Albert's  Fir,  Western  Hemlock  Fir,  California  Hemlock  Spruce 
(England).2 


l"  Black  Hemlock  (Tsuga  mertensiana)  (United  States  Forest  Service, 
Silvical  Leaflet  No.  31,  1908). 

2  "The  Western  Hemlock,"  Allen  (United  States  Forestry  Bureau, 
Bulletin  No.  33);  "Mechanical  Properties  of  Western  Hemlock,"  Goss 
(United  States  Forest  Service,  Bulletin  No.  115). 


80  ORGANIC  STRUCTURAL  MATERIALS 

Hemlock.  Tsuga  canadensis  (L.)  Carr 

NOMENCLATURE  (Sudworth).  Hemlock  Spruce  (Vt.,  R.  I.,  N.  Y., 

Hemlock     (local     and     common  Pa.,  N.  J.,  W.  Va.,  N.  C.,  S.C.) 

name). 

Spruce  (Pa.,  W.  Va.). 
Spruce    Pine     (Pa.,     Del.,     Va., 
N.  C.,  Ga.). 

LOCALITIES. 

Eastern  and  central  Canada,  southward  to  North  Carolina  and  Tennessee. 

FEATURES  OF  TREE. 

Sixty  to  eighty  or  more  feet  in  height;  two  or  three  feet  in  diameter;  short 
leaves,  green  above  and  white  beneath;  straight  trunk,  beautiful 
appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish  brown;  sapwood  distinguishable;  coarse,  pronounced, 
usually  crooked  grain. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  not  strong  or  durable,  brittle,  difficult  to  work;  the  wood 
splinters  easily;  it  retains  nails  firmly. 

REPRESENTATIVE  USES  OF  WOOD. 

Coarse  lumber,  joists,  rafters,  laths,  plank  walks,  and  railway  ties. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

26. 
MODULUS  OF  ELASTICITY. 

1,270,000. 
MODULUS  OF  RUPTURE. 

10,400. 
REMARKS. 

The  specific  name  canadensis  refers  to  Canada,  the  locality  where  these 
trees  excel.  See  also  "The  Eastern  Hemlock,"  Frothingham  (United 
States  Department  of  Agriculture,  Bulletin  No.  152,  1915).  The 
Southern  or  Carolina  Hemlock  (Tsuga  caroliniana)  yields  wood 
that  resembles  that  of  Hemlock. 


LARCH  OR  TAMARACK 

Larix 

The  Eastern  Larch  (Larix  americand)  grows  in  low,  wet  areas 
known  as  tamarack  swamps.  The  Western  species  (Larix 
occidentalis)  grows  where  it  is  dry  and  the  European  Larch  (Larix 
europcea)  also  thrives  upon  dry  soil. 

Many  interesting  records  exist  with  regard  to  the  wood,  which 
was  apparently  known  and  prized  centuries  ago.  It  was  men- 
tioned by  Pliny,  and  Vitruvius  wrote  of  a  bridge,  which  having 
burned,  was  replaced  by  one  of  Larch,  because  it  was«  thought 
that  that  wood  would  not  burn  as  readily.  Some  of  the  piles 
upon  which  the  city  of  Venice  is  founded  are  said  to  be  of  larch.1 
While  seemingly  authoritative,  such  statements  should  be  re- 
ceived with  caution,  since  the  names  of  woods  mentioned  by 
ancient  writers  are  not  always  those  employed  at  the  present 
time. 

Larch  wood  is  hard  and  very  durable.  In  structure  it  resem- 
bles spruce,  and  in  weight  and  appearance  it  resembles  hard  pine. 
The  tall,  straight  trunks  are  so  slender  that  they  are  seldom  cut 
up  into  lumber.  The  trunks  are  usually  used  for  poles,  posts, 
and  railway  ties.  Although  the  Eastern  species  is  usually  found 
in  deep  swamps,  it  often  grows  better  on  drier  ground.  A 
swamp  specimen  required  forty-eight  years  to  reach  a  diameter 
of  two  inches,  while  another  specimen,  located  where  there  was 
less  water,  was  eleven  inches  thick  at  the  end  of  thirty-eight 
years.  The  European  Larch  is  often  employed  in  American 
landscape  effects. 

The  foliage  of  the  Larch  is  shed  every  autumn,  and,  for  this 
reason,  Larch  trees  are  not  truly  " evergreen."  The  tufts  of 
small  needle-like  leaves  are  of  a  fresh  pea-green  color  when  they 
first  appear  in  the  spring,  and  the  trees  are  then  very  beautiful. 
The  trees  present  a  somewhat  gloomy  appearance  in  the  winter. 
Larch  trees  are  very  hardy,  and  the  species  deserves  more  atten- 
tion than  it  receives. 

81 


82  ORGANIC  STRUCTURAL  MATERIALS 

The  European  Larch  (Larix  europcea)  is  a  native  of  central 
Europe.  The  trees  thrive  upon  dry  soil  and  are  used  in 
American  landscape  work.  They  are  good  coniferous  trees  to 
plant  near  houses,  because  they  lose  their  leaves  during  the 
winter.  The  wood  is  similar  to  that  obtained  from  American 
species.  The  European  Larch  yields  the  Venice  turpentine  of 
commerce.  This  substance,  once  collected  through  Venetian 
markets,  is  now  largely  drawn  from  America.  See  also 
"  European  Larch,"  Pinchot  (United  States  Forest  Service, 
Circular  No.  70). 


1  Pliny,  XVI,  43-49  and  XVI,  30;  also  Vitruvius  II,  9;  also  Encyclo- 
paedia Britannica,  Vol.  XIV,  p.  310;  and  "Forestry  in  Minnesota,"  Green. 


CONIFEROUS  TRUNKS  AND  WOODS  83 

/  Larix  americana  Michx. 

Tamarack,  Larch.    <  T     .    7     ..      fr.     D  .,.  ^    , 
\  Larix  lancina  (Du  Roi)  Koch 

NOMENCLATURE  (Sudworth).  Black  Larch,    Red   Larch    (Minn., 

Tamarack,      Larch,       American  Mich.). 

Larch      (local     and     common         Juniper  (Me.,  Canada). 

names). 
Hackmatack  (Me.,  N.  H.,  Mass., 

R.  I.,  Del.,  111.,  Mich.) 

LOCALITIES. 

From  Newfoundland,  Labrador,  and  Alaska,  southward  to  New  York, 

Pennsylvania,  and  Minnesota 
FEATURES  OF  TREE. 

Seventy  to  ninety  feet  high;  one  to  three  feet  in  diameter;  short,  pea-green, 
deciduous  leaves  in  tufts ;  a  slender  tree,  winter  aspect  gloomy. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown;  sapwood  nearly  white;  coarse,  conspicuous  grain; 
compact  structure;  annual  layers  pronounced. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  very  strong,  and  durable;  resembles  spruce. 

REPRESENTATIVE  USES  OF  WOOD. 

Railway  ties,  fence-posts,  sills,  ship-timbers,  telegraph  poles,  flagstaffs,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

38. 
MODULUS  OF  ELASTICITY. 

1,790,000 
MODULUS  OF  RUPTURE. 

12,800. 
REMARKS. 

Almost  all  of  the  comparatively  slender  logs  are  used  for  poles,  masts, 
posts,  and  railway  ties.  Very  few  of  them  are  cut  up  into  lumber.  Lumber- 
men sometimes  divide  tamarack  logs  as  they  are  "Red"  or  " White." 
Red  Tamarack  is  thought  to  be  better  and  more  durable  than  White  Tama- 
rack. This  distinction  is  probably  due  to  differences  in  the  ages  of  the  trees. 
Tamarack  trees  grow  in  swamps,  known  as  Tamarack  Swamps,  which  are 
often  very  extensive.  See  also  "Transactions  American  Institute  of  Mining 
Engineers"  (Vol.  XXIX,  p.  157). 

^ee  also  "Tamarack,  Larix  laricina  (Du  Roi),"  Koch  (United  States 
Forest  Service,  Silvical  Leaflet  No.  32,  1908). 


84  ORGANIC  STRUCTURAL  MATERIALS 

Tamarack,  Larch.      Larix  occidentalis  Nutt. 

NOMENCLATURE  (Sud worth).  Western    Larch,     Great     Western 

Tamarack,     Larch     (local     and  Larch,  Red  American  Larch. 

common  names).  Western  Tamarack  (Cal.). 
Hackmatack  (Idaho,  Wash.). 

LOCALITIES. 

Washington  and  Oregon,  intermittently  to  Montana. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  and  twenty-five  feet  high;  two  and  one-half  to 
four  feet  in  diameter;  a  large  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  red;  thin  sap  wood  lighter;  coarse-grained;  compact 
structure;  annual  rings  pronounced. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Hard,  heavy,  strong,  and  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

Posts,  railway  ties,  and  fuel;  limited  quantity  of  lumber;  similar  to  Larch 
(Larix  americana). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

46. 
MODULUS  OF  ELASTICITY. 

2,300,000. 
MODULUS  OF  RUPTURE. 

17,400. 
REMARKS. 

These  trees  are  much  larger  than  those  of  the  species  Larix  americana. 
They  also  differ,  in  that  they  grow  on  dry  ground,  often  at  compara- 
tively high  elevations.1 


1  See  also  "Mechanical  Properties  of  Western  Larch,"  Goss  (United 
States  Forest  Service,  Bulletin  No.  122);  "Western  Larch,"  Pinchot  (United 
States  Forest  Service  Silvical  Leaflet  No.  14). 


CEDAR 

Cedrus,  Thuya,  Chamcscyparis,  Libocedrus,  Juniperus 

The  name  Cedar  was  first  applied  to  the  true,  foreign,  or 
Lebanon  Cedars  (Cedrus),  but  was  later  applied  to  certain 
Arborvitaes  (Thuya],  Junipers  (Juniperus),  Cypresses  (Chamce- 
cyparis),  and  other  trees1  that  yield  the  durable,  fine-grained 
characteristically  scented  woods  that  are  commonly  known  as 
cedar  woods.  It  is  recorded  that  cedar  was  employed  in  such 
early  constructions  as  the  Temple  of  Solomon  and  the  Temple 
of  Diana  at  Ephesus,2  and  it  is  possible  that  the  product  referred 
to  was  the  same  as  that  to  which  this  name  applies  at  the  present 
time. 

Cedar  is  divided  as  it  is  Red  Cedar  and  White  Cedar. 

Red  Cedar. — A  large  part  of  the  supply  is  derived  from  the  Eastern, 
Western,  and  Southern  species  (Juniperus  virginiana) ,  (Juniperus  scopu- 
lorum),  and  (Juniperus  barbadensis) ,  The  woods  are  soft,  light,  durable, 
fine-grained,  fragrant,  and  of  a  reddish-brown  color.  They  are  some- 
times used  in  construction,  but  are  more  often  employed  in  lead-pencils, 
chests,  and  closets.  The  demand  for  wood  to  be  used  in  lead-pencils 
alone  is  very  great.3  Cedar  chips  and  shavings  are  often  used  in  place 
of  camphor  to  protect  woolens.  The  total  demand  is  greater  than  the 
supply.  Trees  grow  easily  on  almost  any  soil.  They  are  normally 
hardy,  but  are  sometimes  subject  to  disease.4  Some  of  these  diseases 
cease  after  the  trees  have  been  felled  and  the  wood  cut  from  the  diseased 
trees  is  as  durable  as  wood  cut  from  trees  that  are  not  diseased. 

The  Western  Red  Cedar  (Juniperus  scopulorum)  and  the  Southern 
Red  Cedar  (Juniperus  barbadensis)  yield  woods  that  resemble  those 
from  the  Cedar  (Juniperus  virginiana). 

White  Cedar. — Most  " White  Cedar"  is  obtained  from  several  Arbor- 
vitses  and  Cypresses.  The  woods  are  soft,  light,  durable,  fine-grained, 
and  very  inflammable.  They  are  used  for  fence  posts  and  shingles. 
Practically  all  cedar  that  is  not  red  cedar,  is  white  cedar.  White  cedar 
railway  ties  are  defective  because  they  crush  and  cut  under  the  rails 
and  because  they  do  not  hold  spikes.  The  trees  often  grow  in  swamps.5 

85 


86  ORGANIC  STRUCTURAL  MATERIALS 

Some  important  Red  and  White  Cedars  are  as  follows: 

Red  Cedar  White  Cedar 

Red  Cedar  (Juniperus  virginiand) .  Arborvitse  (Thuya  occidentalis) . 
Red  Cedar  (Juniperus  scopulorum).  Canoe  Cedar  (Thuya  gigantea). 
Red  Cedar  (Juniperus  barbadensis) .  White  Cedar  (Chamcecyparis  thy- 

oides). 
Port  Orford  Cedar  (Chamcecyparis 

lawsoniand) . 
Yellow  Cedar  (Chamoecyparis  nut- 

katensis). 

Incense  Cedar  (Libocedrus  decur- 
rens) . 

1  See  "Spanish  Cedar"  (Cedrela  odorata}. 

2  Pliny,  16,  213,  and  16,  216. 

3  "Notes  on  Red  Cedar,"   Mohr  (United  States  Division  of  Forestry, 
Bulletin  No.  31).     See  also  "Uses  of  Commercial  Woods  of  United  States: 
1,  Cedars,  Cypresses,  and  Sequoias"  (United  States  Forest  Service,  Bulletin 
No.  95,  1911). 

4  Two  diseases  are  recognized.     They  are  white  rot,  caused  by  Polyporus 
Juniperus,  and  red  rot,  caused  by  Polyporus  carneus,  von  Schrenk  (United 
States  Division  Vegetable  Physiology  and  Pathology,   Bulletin  No.  21); 
also  von  Schrenk,  Shaw  School  of  Botany,  Contribution  No.  14  (St.  Louis, 
Mo.). 

5  Timbered  swamps  are  very  formidable.     For  example,  the  "  White  Cedar 
swamp,"  of  the  Lake  Superior  region,  is  covered  close  down  to  the  ground,  by 
the  vigorous  branches  of  the  trees.     These  branches  meet  and  cross  one 
another,  and  passage  through  such  a  district  resembles  passage  through  a  cul- 
tivated hedge.     The  roots  lie  partly  out  of  the  water,  and,  while  apparently 
sound,  are  slippery  and  sometimes  decayed,  so  that  the  pedestrian,  stepping 
or  springing  from  one  root  to  another,  encumbered  by  burdens,  and  ob- 
structed by  the  wiry  branches,  is  liable  to  slip  and  fall.     The  constant  use  of 
arms  and  legs,  with  the  shock  caused  by  packs  shifting  upon  the  shoulders 
when  the  pedestrian  falls,  and  the  annoying  insects,  require  much  strength 
and  patience.     Such  Northern  swamps  can  best  be  penetrated  during  the 
winter  season,  when  the  ground  is  frozen.     The  "Tamarack  swamp"  of  the 
North  differs  from  the  "  White  Cedar  swamp,"  in  that  the  lower  branches  of 
the  Tamarack  are  higher  from  the  ground.     The  "Cypress"  is  the  charac- 
teristic swamp  tree  of  the  South. 


CONIFEROUS  TRUNKS  AND  WOODS  87 

Red  Cedar.  Juniperus  virginiana  Linn. 

NOMENCLATURE  (Sudworth).  Savin   (Mass.,   R.   I.,   N.   Y.,   Pa., 

Red   Cedar   (local  and  common  Minn.). 

name).  Juniper,  Red  Juniper,  Juniper  Bush 

Cedar  (Conn.,  Pa.,  N.  J.,  S.  C.,  (local). 

Ky.,  111.,  la.,  Ohio). 
Pencil  Cedar,  Cendre  (La.). 

LOCALITIES. 

Atlantic  Coast,  Canada  to  Florida,  westward  intermittently  to  the  Mississ- 
ippi River  in  the  North  and  the  Colorado  River  in  the  South. 

FEATURES  OP  TREE. 

Fifty  to  eighty  feet  in  height;  two  to  three  feet  in  diameter;  dark-green, 
scale-like  foliage;  loose,  ragged,  outer  bark. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dull-red;  thin  sapwood  nearly  white;  close,  even  grain;  com- 
pact structure;  annual  layers  easily  distinguishable. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  weak,  and  brittle;  easily  worked;  durable;  fragrant;  the  fra- 
grance is  such  that  the  wood  is  used  as  an  insecticide. 

REPRESENTATIVE  USES  OF  WOOD. 

Ties,  sills,  posts,  interior  finish,  pencil-cases,  chests,  and  cigar-boxes. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

30. 
MODULUS  OF  ELASTICITY. 

950,000. 
MODULUS  OF  RUPTURE. 

10,500. 
REMARKS. 

The  trunks  of  these  trees  are  sometimes  attacked  by  fungi  similar  to  those 
that  attack  Cypress  and  Incense  Cedar  trees.  The  disease  stops  when 
the  trees  are  felled,  and  boards  cut  from  such  trees  have  been  known  to 
last  for  over  fifty  years.  See  also  Contribution  No.  44,  Shaw  School  of 
Botany,  von  Schrenk;  "Two  Diseases  of  Red  Cedar"  (United  States 
Division  of  Vegetable  Physiology  and  Pathology,  Bulletin  No.  21); 
Mohr  (United  States  Forestry  Bulletin  No.  31);  "Red  Cedar,"  Pinchot 
(United  States  Forest  Service,  Circular  No.  73). 


88  ORGANIC  STRUCTURAL  MATERIALS 

Juniper.  Juniperus  occidentalis  Hook 

NOMENCLATURE  (Sud worth).  Cedar,     Yellow     Cedar,     Western 

Juniper  (Oreg.,  Cal.,  Col.,  Utah,  Cedar  (Idaho,  Col.,  Mont.). 

Nev.,  Mont.,  Idaho,  N.  M.).  Western  Red  Cedar,  Western  Juni- 

per (local). 

LOCALITIES. 

California,  Washington,  Oregon,  and  Idaho. 

FEATURES  OF  TREE. 

Twenty-five  to  fifty  feet  in  height;  two  to  four  feet  in  diameter;  often 
smaller. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish-brown;  sapwood  nearly  white;  very  close-grained; 
compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Ligfct,  soft,  and  durable;  receives  a  high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 
Fencing,  railway  ties,  posts,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

35. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 

REMARKS. 

Rarely  found  below  an  altitude  of  six  thousand  feet.     Fruit  said  to  be 
eaten  by  Indians. 


The  California  Juniper  (Juniperus  californica)  grows  intermittently  in 
some  districts  in  California,  near  the  coast  line.  The  trees  are  sometimes 
as  much  as  thirty  or  forty  feet  in  height,  and  one  or  two  feet  in  diameter,  but 
are  often  much  smaller.  The  shaggy  bark  is  of  a  grayish  color.  The  soft, 
close-grained,  fragrant,  durable  wood  has  been  used  to  meet  minor  needs. 


CONIFEROUS  TRUNKS  AND  WOODS  89 

White  Cedar,  Arborvitae.  Thuya  occidentalis  Linn. 

NOMENCLATURE  (Sudworth).  Atlantic  Red  Cedar  (Cal.). 

White    Cedar,    Arborvitse    (local         Vitse  (Del.). 

and  common  names). 
Cedar  (Me.,  Vt.,  N.  Y.). 

LOCALITIES. 

Northern  States,  eastward  from  Manitoba  and  Michigan;  northward,  also 
occasionally  southward,  as  in  the  mountain  region  of  North  Carolina 
and  eastern  Tennessee. 

FEATURES  OF  TREE. 

Thirty  to  sixty  feet  high;  one  to  three  or  more  feet  in  diameter;  often 
smaller;  bruised  leaves  emit  a  characteristic  pungent  odor;  the  trunks 
taper  rapidly. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown,  darkening  with  exposure;  the  thin  sapwood  is 
nearly  white;  even,  rather  fine  grain;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  light,  weak,  brittle,  durable,  and  inflammable;  does  not  hold  spikes 
firmly. 

REPRESENTATIVE  USES  OF  WOOD. 
Railway  ties,  telegraph  poles,  posts,  fencing,  shingles,  and  boats. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

19. 
MODULUS  OF  ELASTICITY. 

750,000. 
MODULUS  OF  RUPTURE. 

7,200. 
REMARKS. 

The  comparatively  slender  trunks  are  seldom  cut  up  into  lumber,  but  are 
used  for  poles;  or  else,  the  thin,  upper  ends  are  used  for  posts,  and  the 
lower  parts  are  flattened  and  used  for  ties.  The  wood  is  remarkably 
durable.  Hough  describes  a  prostrate  cedar  tree  over  the  trunk  of 
which  a  hemlock,  which  later  exhibited  one  hundred  and  thirty  yearly 
bands,  had  taken  root.  The  cedar  tree  had  evidently  been  in  contact 
with  the  ground  for  at  least  one  hundred  and  thirty  years,  yet  much  of 
its  wood  was  sound  enough  to  be  cut  up  into  shingles. 


90     ,  ORGANIC  STRUCTURAL  MATERIALS 

Canoe  Cedar,  Arborvitae,          Thuya  plicata  Don. 
Giant  Arborvitae.  Thuya  gigantea  Nutt. 

NOMENCLATURE    (Sudworth).  Cedar,  Giant  Cedar,  Western  Cedar 

Canoe   Cedar,    Giant   Arborvitse  (Oreg.,  Cal.). 

(local  and  common  names).  Shinglewood  (Idaho). 

Red    Cedar,    Giant    Red    Cedar, 

Pacific     Red    Cedar     (Wash., 

Oreg.,  Cal.,  Idaho). 

LOCALITIES. 

Coast  region,  California  to  Alaska,  Idaho  to  Montana. 

FEATURES  OF  TREE. 

One  hundred  to  two  hundred  feet  in  height;  two  to  eleven  feet  in  diameter; 
the  trunks  are  often  buttressed  at  the  surface  of  the  ground;  the  tiny, 
bright  green  leaves  are  scale-like. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dull  reddish  brown;  the  thin  sapwood  is  nearly  white;  coarse- 
grained; compact  structure;  annual  layers  distinct. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  weak,  light,  brittle,  easily  worked,  and  very  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

Shingles,  fencing,  cooperage,  interior  finish  and  canoes. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

23. 
MODULUS  OF  ELASTICITY. 

1,460,000. 
MODULUS  OF  RUPTURE. 

10,600. 
REMARKS. 

The  large  parts  at  the  bottoms  of  the  trees  are  usually  hollow. 


See  also  "Giant  Arborvitae  Thuya  plicata  Don,"  (United  States  Forest 
Service  Silvical  Leaflet  No.  11,  1907);  "  Western^Red  Cedaiy^  Detwiler 
(American  Forestry,  March,  1916). 


CONIFEROUS  TRUNKS  AND  WOODS  91 

White  Cedar.  Chamcecyparis  thyoides  L. 

NOMENCLATURE  (Sudworth).  Post  Cedar,  Swamp  Cedar  (Del.). 

White  Cedar  (local  and  common         Juniper  (Ala.,  N.  C.,  Va.). 
name). 

LOCALITIES. 

Maine  to  Florida,  Gulf  Coast  to  Mississippi;  best  in  Virginia  and  North 
Carolina. 

FEATURES  OF  TREE. 

Sixty  to  eighty  feet  in  height;  three  to  four  feet  in  diameter;  shaggy, 
rugged  bark;  a  graceful  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood    pinkish   brown   to   darker   brown;  sap  wood  lighter;  close- 
grained;  compact  structure;  conspicuous  layers. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Very  light  and  soft;  not  strong;  extremely  durable  in  exposed  positions; 
fragrant;  easily  worked;  White  Cedar  posts  last  for  many  years. 

REPRESENTATIVE  USES  OF  WOOD. 

Boats,  railway  ties,  fencing,  poles,  posts,  and  shingles. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
23  (United  States  Forestry  Division).1 
20. 

MODULUS  OF  ELASTICITY. 

910,000  (average  of  87  tests  by  United  States  Forestry  Division).1 
570,000. 

MODULUS  OF  RUPTURE. 

6,310  (average  of  87  tests  by  United  States  Forestry  Division).1 
6,400. 

REMARKS. 

These  trees  often  grow  in  swamps,  as  see  footnote,  page  86. 

p.  33. 


92  ORGANIC  STRUCTURAL  MATERIALS 

Port  Orford  Cedar,  Lawson  Cypress.     Chamcecyparis  lawsoniana  Murr. 

NOMENCLATURE  (Sudworth). 

White     Cedar,     Oregon     Cedar,  Ginger  Pine  (Cal.). 

(Oreg.,  Cal.). 

LOCALITIES. 

Pacific  Coast,  California  and  Oregon. 

FEATURES  OF  TREE. 

One  hundred  to  sometimes  two  hundred  feet  in  height;  four  to  ten  feet  in 
diameter;  the  leaves  overlap  in  sprays;  the  very  small  cones  are  one- 
fourth  of  an  inch  in  diameter. 1 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  yellowish-white;  sapwood  similar;  very  close-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  hard;  strong,  durable,  and  easily  worked;  fragrant;  resinous. 

REPRESENTATIVE  USES  OF  WOOD. 
Lumber,  flooring,  interior  finish,  ties,  posts,  matches,  and  shipbuilding. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,730,000. 
MODULUS  OF  RUPTURE. 

12,600. 
REMARKS. 
The  resin  is  employed  as  an  insecticide. 


xSee  also  "Port  Orford  Cedar,"  Pinchot  (United  States  Silvical  Leaflet 
No.  2). 


The  Yew  (Taxus)  yields  a  close-grained  wood  that  suggests  Cedar,  save 
that  it  is  tough  like  Hickory.  The  early  Celtic  races  associated  Yew  trees 
with  funerals.  The  wood  was  one  of  the  "fighting  woods"  of  the  Greeks. 
The  best  Yew  bow-staves  came  from  Italy,  Turkey  and  Spain,  and  were  dis- 
tributed through  the  Venetian  markets.  Spanish  staves  were  once  so  impor- 
tant that  they  were  controlled  by  the  Spanish  Government.  More  recently, 
European  bows  were  backed  with  other  and  more  plentiful  woods.  Yew  is 
now  occasionally  employed  for  chairs,  canes,  and  whips. 

Pacific  Coast  Indians  prized  the  Western,  Oregon,  or  California  Yew 
(Taxus  brevifolia)  for  bows,  paddles,  and  fish  hooks.  The  Florida  Yew 
(Taxus  floridana)  is  another  United  States  species.  Ernest  Thompson  Seton 
classes  American  woods  suitable  for  bows  in  order  of  excellence  as  follows: 
"Oregon  Yew,  Osage  Orange,  White  Hickory,  Elm,  Cedar,  Apple,  etc." 


CONIFEROUS  TRUNKS  AND  WOODS^  93 

Yellow  Cedar,  Yellow  Cypress,  Sitka  Cypress. 

f  Chamcecyparis  nootkatensis  (Lamb)  Spach 
\  Chamcecyparis  nutkaensis  Spach 

NOMENCLATURE  (Sudworth). 

Nootka  Cypress,  Nootka  Sound         Alaska    Cypress,    Alaska    Ground 
Cypress  (local).  Cypress  (local). 

LOCALITIES. 

Oregon  to  Alaska. 

FEATURES  OF  TREE. 

One  hundred  or  more  feet  in  height;  three  to  five  or  more  feet  in  diameter; 
sharp-pointed,  overlapping  leaves;  small,  globular  cones. 

COLOR,  APPEARANCE.  OR  GRAIN  OF  WOOD. 

Heartwood  clear  light  yellow;  thin  sapwood  nearly  white;  close-grained; 
compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  not  strong,  brittle,  and  hard;  durable  in  contact  with  soil;  easily 
worked;  receives  a  high  polish;  fragrant. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  furniture,  and  interior  finish. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

29. 
MODULUS  OF  ELASTICITY. 

1,460,000. 
MODULUS  OF  RUPTURE. 

11,000. 
REMARKS. 

A  valuable  lumber  tree. 


94  ORGANIC  STRUCTURAL  MATERIALS 

Incense  Cedar,  White  Cedar.   (  Libocedrusdecurrens  Torr. 

(  Heydena  decurrens. 
NOMENCLATURE  (Sudworth). 

Post  Cedar,  California  Post  Cedar        California  White  Cedar  (local), 
(local).  Juniper  (Nevada). 

Bastard  Cedar,  Red  Cedar. 

LOCALITIES. 

California,  Lower  California,  Oregon,  and  Nevada. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  and  twenty-five  feet  in  height,  occasionally 
higher;  three  to  six  feet  in  diameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish;  sapwood  lighter;  close-grained;  compact  struc- 
ture; heartwood  often  pitted;  fragrant. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  brittle,  soft,  and  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

t  Flumes,  shingles,  and  interior  finish.      ^e^c^  jM&tjf +"*-  ' 

*  v    *    " 
WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

25. 
MODULUS  OF  ELASTICITY. 

1,200,000. 
MODULUS  OF  RUPTURE. 

960,000. 
REMARKS. 

The  heartwood  of  these  trees  is  often  attacked  by  fungi  that  create  large, 
oval  pits.  The  wood  between  the  decayed  spaces  is  apparently  sound, 
even  in  living  trees.  The  disease  stops  when  the  trees  are  felled,  and 
the  wood  that  remains  is  so  durable  that  it  can  be  used  for  posts 
or  for  other  purposes  where  appearance  is  not  important.  Some 
dealers  charge  as  much  for  wood  with  pits  as  for  that  without  pits. 
This  disease  is  similar  to  the  diseases  that  attack  Cypress  and  Red 
Cedar.  It  is  said  that  about  one-half  of  the  standing  supply  of  In- 
cense Cedar  has  been  affected  by  this  disease,  which  is  popularly  known 
as  "pin  rot"  (see  also  von  Schrenk,  Contribution  No.  14,  Shaw  School 
of  Botany). 


CYPRESS 

Cupressus  and  Taxodium 

The  name  Cypress  has  been  applied  to  trees  of  the  genera 
Chamcecyparis,  Cupressus,  and  Taxodium.  Most  of  the  species 
of  the  genus  Chamcecyparis  are  now  classed  as  Cedars.  The 
genus  Cupressus  includes  true  Cypresses,  and  is  important  in 
Europe,  but  the  trees  themselves,  rather  than  their  woods,  are 
valued  in  the  United  States.  The  single  species  of  the  genus 
Taxodium  is  not  a  Cypress,  but  the  trees  of  this  species  supply 
the  " cypress  wood"  of  American  commerce.  The  name  Cypress 
will  be  applied  only  to  the  true  Cypresses  (Cupressus),  and  to 
the  commercial  Cypress  (Taxodium). 

True  cypress  wood  is  mentioned  by  Herodotus  and  other  an- 
cient authors,  and  is  construed  by  some  to  have  been  the  "  Gopher 
wood"  of  which  the  Ark  was  built.1  Pliny  mentions  cypress 
doors  that  were  good  after  four  hundred  years,  and  a  cypress 
statue  that  was  preserved  for  six  hundred  years.  It  is  said  that 
the  cypress  gates  of  the  early  Saint  Peter's,  removed  after  one 
thousand  years  of  service,  were  found  to  be  in  excellent  condi- 
tion.2 Cypress  wood  has  been  prized  for  mummy  cases,  and 
cypress  trees  are  yet  planted  as  funeral  emblems  over  graves  in 
Turkey  and  in  Italy.3  The  common  or  evergreen  Cypress  is  the 
principal  species  in  Europe.  The  eight  or  nine  American  species 
(Cupressus)  do  not  produce  valuable  woods,  but  the  trees  are 
sometimes  used  for  ornamentation,  as  in  hedges. 

The  Monterey  Cypress  (Cupressus  macrocarpa)  is  evidenced  by  a 
group  of  trees  that  includes  the  only  original  specimens  of  this  species 
that  survive  in  the  United  States.  The  famous  " seventeen  mile  drive" 
near  Monterey,  California,  passes  through  the  district  in  which  these 
trees  are  located.  Their  weird  forms,  with  gnarled,  wind-beaten 
branches,  are  very  unusual.  The  fact  that  transplanted  specimens  of 
the  Monterey  Cypress  grow  so  readily  in  many  places  on  the  Pacific 
Coast  is  hard  to  reconcile  with  the  further  fact  that  so  few  of  the  original 
trees  remain  at  the  present  time. 

95 


96  ORGANIC  STRUCTURAL  MATERIALS 

American  Cypress  wood  is  obtained  from  the  Bald  Cypress 
(Taxodium  distichum)  which  grows  on  submerged  lands  and  in 
deep  swamps,  making  unusual  logging  methods  necessary.  The 
trees  are  subject  to  a  peculiar  fungus  disease  that  causes  cavities 
such  as  would  be  made  by  driving  pegs  into  the  wood  and  then 
withdrawing  them,  and  wood  thus  affected  is  known  as  "peggy 
cypress."  The  disease  ceases  as  soon  as  trees  are  felled,  and 
wood  then  cut  from  them  is  as  durable  as  wood  cut  from  per- 
fectly healthy  trees.  About  one-third  of  the  standing  supply  is 
affected.  American  Cypress  wood  has  many  names.  Pieces 
that  float  and  pieces  that  sink  in  water  have  been  classed  as 
White  Cypress  and  Black  Cypress  respectively.  All  dark 
pieces  are  now  classed  as  Black  Cypress,  while  the  tinted  woods 
are  sometimes  sold  under  the  names  of  Red  Cypress  and  Yellow 
Cypress.4 

The  Bald  Cypress  bears  needle-like  leaves,  which  are  about 
three-fourths  of  an  inch  in  length,  and  separated  from  one 
another.  They  are  not  arranged  in  tufts  as  in  the  case  of  the 
larch,  yet  the  foliage  resembles  that  of  the  larch,  in  that  it  is 
shed  at  the  end  of  the  season.  The  name  Bald  Cypress  is  due  to 
the  appearance  of  the  trees  after  the  leaves  have  fallen.  The 
roots  that  appear  above  the  surface  of  the  surrounding  soil  or 
water  are  known  as  " cypress  knees." 


1  Pliny,  16,  214  and  16,  215;  Herodotus,  4,  16;  Virgil,  Georgics,  2,  443. 
Funk  &  Wagnalls'  Standard  Dictionary,  quoting  Horace  Smith,  "Gayeties 
and  Gravities,"  Chapter  VII,  p.  57. 

2  Encyclopaedia  Britannica,  B.  6,  p.  745. 

3  Brockhaus,  Konversations-Lexikon,  B.  4,  p.  654. 

4  See  also  von  Schrenk,  (Contribution  No.  14,  Shaw  School  of  Botany); 
"Uses  of  Commercial  Woods  of  the  United  States,"   Hall  and  Maxwell 
(United  States  Forest  Service,  Bulletin  No.  95,  1911);  "The  Cypress  and 
Juniper  Trees  of  the  Rocky  Mountain  Region,"  Sudworth  (United  States 
Department  of  Agriculture,  Bulletin  No.  207);  "The  Southern  Cypress," 
Matoon  (United  States  Department  of  Agriculture,  Bulletin  No.  272,  1915); 
"The  Bald  Cypress,"  Detwiler  (American  Forestry,  October,  1916). 


CONIFEROUS  TRUNKS  AND  WOODS  97 

Cypress,  Bald  Cypress.     Taxodium  distichum  Rich. 
NOMENCLATURE  (Sudworth). 

White  Cypress  (N.  C.,  S.  C.,  Fla.,         Swamp  Cypress  (La.). 

Miss.).  Deciduous  Cypress  (Del.,  111.,  Tex.). 

Black  Cypress  (N.  C.,  S.  C.,  Ala.,         Southern  Cypress  (Ala.). 

Tex.). 
Red  Cypress  (Ga.,  Miss.,  La.,  Tex.). 

LOCALITIES. 

South  Atlantic  and  Gulf  States,  Maryland,  through  Florida  to  Texas, 
Mississippi  Valley  from  southern  Illinois  to  the  Gulf.  Forms  forests 
in  swamps  and  barrens.1 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  and  fifty  feet  in  height;  four  to  ten  feet  in  diame- 
ter; the  knees  on  the  roots  often  become  hollow  with  old  age;  the 
leaves  are  flat  and  deciduous. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish;  sapwood  nearly  white;  close,  straight  grain;  the 
trunks  are  frequently  pitted  by  disease. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light  and  soft;  not  strong;  durable;  green  wood  is  often  very  heavy. 

REPRESENTATIVE  USES  OF  WOOD. 

Carpentry,  construction,  cooperage,  and  railway  ties. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
29  (United  States  Forestry  Division).1 

28. 

MODULUS  OF  ELASTICITY. 

1,290,000  (average  of  655  tests  by  United  States  Forestry  Division).2 
1,460,000. 

MODULUS  OF  RUPTURE. 

7,900  (average  of  655  tests  by  United  States  Forestry  Division).2 
9,600. 

REMARKS. 

Cypress  is  of  ten  divided  into  "White  Cypress"  and  "Black  Cypress," 
the  difference  being  probably  due  to  differences  in  the  ages  and  environ- 
ment of  the  trees  from  which  these  two  grades  were  cut.  Cypress 
trees  are  often  attacked  by  fungi  that  create  pits  in  the  wood.  The 
disease  stops  when  the  trees  are  felled,  and  the  wood  that  remains  is  very 
durable.  This  disease  is  similar  to  others  that  attack  Incense  Cedar 
trees  and  Red  Cedar  trees. 

1  See  "Transactions    American    Institute   of    Mining   Engineers"   (Vol. 
XXIX,  p.  157). 

2  See  p.  33. 

7 


REDWOOD 

Sequoia 

These  trees  grow  in  California.  There  are  two  species  as 
follows : 

The  Common  Redwood  (Sequoia  sempervirens)  grows  near  the 
coast  line  where  it  is  said  to  " follow  the  fogs."  The  trees  are 
large  and  very  perfect.  The  soft,  light,  clean,  reddish-brown 
wood  works  easily  and  can  be  obtained  in  large-sized  pieces. 


Fio.  29. — Assembling  parts  of  redwood  stave  pipe. 

The  wood  resists  fire  more  than  many  others  and  is  extremely 
durable  in  exposed  places.  It  repels  some  forms  of  terrestrial 
wood-borers,  but  has  given  way  before  the  attacks  of  shipworms. 
It  is  used  for  fence  posts,  railway  ties,  water-pipes,  house-trim, 
flumes,  coffins,  and  shingles.  Average  pieces  are  often  used  in 
cheaper  forms  of  indoor  finish,  while  unusual  and  attractive 
pieces,  in  which  grain  is  distorted,  are  classed  as  Curly  Redwood 
and  preferred  in  a  better  grade  of  work. 


CONIFEROUS  TRUNKS  AND  WOODS  99 

Some  of  the  trees  of  this  species  are  so  large  that  they  have  been  con- 
fused with  the  exceptional  or  "giant"  specimens  of  the  Mammoth  Red- 
wood. The  fire-resisting  qualities  of  the  wood  were  shown  in  the  build- 
ings that  existed  in  San  Francisco  before  the  earthquake.  Redwood 
was  largely  employed  in  these  buildings,  yet  comparatively  few  fires 
took  place  until  the  conflagration  caused  by  the  earthquake.  Durability 
is  shown  by  trunks  that  fell  in  the  forests  one  hundred  or  more  years 
ago.  Some  of  these  trunks  not  only  have  not  rotted,  but  contain  good 
wood  that  can  be  used  in  construction.  Resistance  to  attacks  by  land 
wood-borers  is  shown  by  the  stave-pipes  used  in  irrigation  work  in  the 
West.  These  pipes  usually  remain  safe  from  attack  as  long  as  the  wood 
remains  wet  and  in  use.  It  should  be  noted,  however,  that  they  are 
sometimes  attacked  by  termites  while  dry. 


FIG,  30. — Completed  redwood  stave  pipe  with  gate. 

The  Mammoth  Redwood  (Sequoia  washingtoniana)  is  found 
inland  where  there  is  less  moisture.  Some  of  the  trees  are  the 
most  massive,  although  not  the  tallest,  trees  known  to  man. 
Individuals  three  hundred  and  twenty  feet  high  and  thirty-five 
feet  in  diameter  have  been  measured.  It  is  estimated  that  some 
specimens  twenty-five  feet  in  diameter  were  thirty-six  hundred 
years  old,  and  it  is  thought  probable  that  under  favorable  condi- 
tions such  trees  could  have  survived  for  a  total  of  five  thousand 
years.  The  almost  non-inflammable  bark  is  sometimes  nearly 
two  feet  in  thickness.  Even  the  oldest  trees  are  sound  through- 
out. The  wood  is  brittle,  but  otherwise  resembles  and  is  seldom 


100  ORGANIC  STRUCTURAL  MATERIALS 

distinguished  commercially  from  the  wood  of  the  Common  Red- 
wood. Many  of  the  smaller  trees  of  this  species  are  cut  down 
every  year,  but  the  largest  trees  are  now  protected  or  used  for 
exhibition  purposes.  Most  of  these  exceptional  trees  have 
names  such  as  the  " Pride  of  the  Forest/'  the  ''Grizzly  Giant," 
and  the  "U.  S.  Grant."  These  exceptional  specimens,  which  do 
not  exceed  several  hundred  in  number,  are  grouped  in  the  Mari- 
posa,  Calavaras,  and  other  groves. 

The  genus  is  notable,  first,  because  of  the  present  value  of  the 
wood,  and  second,  because  the  quick-growing,  healthy  trees  are 
likely  to  resist  commercial  extinction.  The  name  Sequoia  is 
that  of  an  Indian  Chief.  Redwood  trees  may  be  known  by  their 
size  and  locality,  and  also  by  their  fine,  dull,  evergreen  leaves.1 


^ee  also  "The  Big  Trees  of  California"  (United  States  Forestry  Division 
Bulletin  No.  28);  "The  Bigtree,"  Sudworth  (United  States  Forest  Serv- 
ice Silvical  Leaflet  No.  19);  "Redwood"  (United  States  Forest  Service 
Bulletin  No.  38);  "Mechanical  Properties  of  Redwood,"  Heim  (United 
States  Forest  Service,  Circular  No.  193,  1912);  "The  Secret  of  the  Big 
Trees,"  Huntington  (United  States  Department  of  Interior,  Document); 
"Uses  of  Commercial  Woods  of  the  United  States,"  Hall  and  Maxwell 
(United  States  Forest  Service,  Bulletin  No.  95,  1911). 


CONIFEROUS  TRUNKS  AND  WOODS  101 

Redwood.     Sequoia  sempervirens  (Lamb.}  Endl. 
NOMENCLATURE  (Sudworth). 

Redwood  (local  and  common  Sequoia,  California  Redwood,  Coast 
name).  Redwood  (local). 

LOCALITIES. 

Central  and  North  Pacific  Coast  region. 

FEATURES  OF  TREE. 

Two  hundred  to  three  hundred  feet  in  height,  sometimes  higher;  six  to 
eight  and  sometimes  twenty  feet  in  diameter;  straight,  symmetrical 
trunk;  low  branches  are  rare. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heart  wood  red,  changing  to  reddish  brown  when  seasoned;  thin 
sapwood  nearly  white;  coarse,  normally  straight  grain;  compact 
structure;  very  thick  bark. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light  and  soft;  not  strong;  very  durable;  easily  worked,  and  receives  a  high 
polish;  not  resinous,  and  does  not  burn  easily. 

REPRESENTATIVE  USES  OF  WOOD. 

Timber,  shingles,  flumes,  fence-posts,  coffins,  railway  ties,  water-pipes, 
and  interior  decoration;  the  bark  is  made  into  souvenirs. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
26  (Census  figure,  see  p.  33). 

MODULUS  OF  ELASTICITY. 

790,000  (average  of  8  Humboldt  specimens).1 
1,140,000  (average  of  7  Humboldt -specimens).1 
960,000  (Census  figure,  see  p.  33). 

MODULUS  OF  RUPTURE. 

4,920  (average  of  9  Humboldt  specimens).1 
7,138  (average  of  7  Mendocino  specimens).1 
8,400  (Census  figure,  see  p.  33). 

REMARKS. 

Redwood  is  the  principal  construction  wood  of  California.  Occasional 
pieces  with  curled  or  distorted  grain  are  valued  for  minor  cabinet 
work. 


The  Bigtree,  Mammoth  Tree,  or  Giant  Redwood  (Sequoia  washingtoniana) 
is  the  largest  tree  known  to  man.  The  wood,  which  resembles  that  of  the 
Common  Redwood,  is  used  locally.  See  also  "  Bigtree,  Sequoia  washing- 
toniana (Winsl.)  Sudw."  (United  States  Forest  Service,  Silvical  Leaflet 
No.  19,  1908);  etc.,  etc. 

1  Soule,  Transactions  American  Institute  of  Mining  Engineers  (California 
Meeting,  1899). 


CHAPTER  VI 

BANDED  TRUNKS  AND  WOODS  (CONTINUE.  ) 
BROADLEAF  SERIES.     PART  ONE 

Dicotyledons 

The  trees  of  the  Broadleaf  Series  grow  in  natural  forests  and 
under  cultivation  in  many  parts  of  the  world.  The  Oaks, 
Elms,  Maples,  and  other  so-called  hardwood  trees  are  of  this 
group. 

Broadleaf  woods  are  comparatively  heavy  in  weight  and,  in 
most  cases,  the  arrangement  of  the  wood-elements  is  more  com- 
plicated than  in  the  woods  of  the  Coniferous  series.  Broadleaf 
woods  are  difficult  to  work  in  proportion  as  they  are  complicated 
in  cellular  structure.  Tiemann  has  compared  the  cellular  struc- 
ture of  broadleaf  woods  with  the  cellular  structure  of  coniferous 
woods  as  follows:1 

"The  wood  of  the  angiosperms  (broadleaf  woods),  on  the  other  hand, 
is  much  more  complex,  as  the  vertical  cells  are  exceedingly  variable 
both  in  size  and  character.  The  vertical  cells,  consisting  of  wood-fibers, 
vessels,  tracheids,  and  others,  in  some  species  of  the  angiosperms,  are 
often  of  four,  or  five  distinct  kinds,  and  vary  in  size  and  shape  from  the 
finest  hair  of  a  few  millimeters  in  length,  to  the  long  vessels  as  large  as 
the  lead  in  a  lead-pencil.  There  are  also  short,  thin-walled  cells  inter* 
spersed.  The  Oak  is  one  of  the  most  complex  woods  in  this  respect? 
while  the  Red  Gum  and  the  Tulip  are  comparatively  simple. 

In  the  Conifers,  it  is  the  tracheids  which  give  the  strength  to  the 
wood,  but  in  the  angiosperms  it  is  the  long,  narrow,  hair-shaped  cells 
or  wood-fibers  which  are  the  chief  parts  of  the  structure  producing  the 
strength.  The  latter  are  usually  grouped  in  bunches  and  form  the 
principal  structural  feature  in  the  angiosperms.  In  the  late  wood  of  the 
annual  rings,  their  walls,  compared  to  their  diameters,  become  exceed- 
ingly thick.  These  also  have  pits,  but  of  a  simpler  kind,  which  are  slit- 
like  and  known  as  "simple  pits." 

Broadleaf  woods  are  used  in  construction,  although  the  greater 
need  as  to  quantity  in  this  field  is  met  by  the  woods  of  the  other 
series.  Woods  for  cabinet  purposes  and  implements  are  drawn 

102 


BROADLEAF  TRUNKS  AND  WOODS  103 

from  the  present  group  which,  with  a  few  exceptions,  cannot  be 
depended  upon  for  the  large,  straight  pieces  so  often  obtained 
from  coniferous  trees. 

The  comparatively  broad  leaves  of  the  trees  of  this  series  are 
usually  distinguished  from  the  more  or  less  needlelike,  resinous 
leaves  of  the  conifers.  Most,  but  not  all,  broadleaf  trees  are 
deciduous,  and  many,  but  not  all,  of  the  woods  are  comparatively 
hard.  The  names  " deciduous"  and  " hardwood"  are  less  satis- 
factory than  the  name  " Broadleaf,"  which  should  be  preferred. 


1 "  Wood  Preservation"  (American  Railway  Engineering  and  Maintenance 
of  Way  Association,  Bulletin  No.  120,  p.  361). 


OAK 

Quercus 

The  Oaks  grow  in  many  parts  of  the  northern  hemisphere,  and 
at  high  altitudes  just  south  of  the  equator.  The  historical 
importance  of  the  wood  was  founded  upon  the  reputation  of  the 
English  Oaks  (Quercus  robur  var.  pedunculata  and  Quercus  robur 
var.  sessili flora)  ,l  which  once  formed  large  forests  over  parts  of 
northern  and  central  Europe. 

The  woods  were  formerly  relied  upon  to  meet  many  needs  in 
ships  and  houses,  and  did  not  give  way  to  iron  for  vessels,  and  to 
the  so-called  softwoods  for  houses,  until  comparatively  recent 
periods.  Practically  all  ships  were  built  of  wood  until  the  battle 
of  the  Merrimac  and  the  Monitor;  and  oaken  timbers  were  used 
in  many  English  houses,  even  of  the  cottage  type,  until  the  sup- 
plies of  softwoods  from  the  Baltic  forests  and  from  those  of  North 
America  became  easily  available.  Oak  is  yet  used  for  railway 
ties  and  high-grade  construction  timbers,  but  to  a  more  limited 
extent  than  formerly;  while  the  demands  for  oak  to  be  used  in 
cabinet  work  are  constantly  increasing. 

Oak  wood  is  tough  and  durable  in  contact  with  the  ground.  It 
receives  a  high  polish  and  is  more  or  less  easily  obtained.  On  the 
other  hand,  it  is  liable  to  warp  and  check  in  seasoning,  and  hard 
to  nail  without  splitting.  It  contains  gallic  acid,  which  attacks 
iron  fastenings.  Experiments  indicate  that  the  iron  is  eventually 
protected  by  the  formation  of  a  scale,  and  that  the  wood,  although 
darkened,  remains  practically  uninjured.  Oak  bark  is  so 
charged  with  gallic  acid  that  it  is  used  in  the  tanning  of  leather. 

An  experiment  made  to  determine  the  effect  of  gallic  acid  upon  iron2 
was  as  follows:  Five  grams  of  clean  iron  wire  were  immersed  in  a  5 
per  cent,  solution  of  gallic  acid.  In  nine  days  the  weight  was  4.720 
grams  and  the  solution  intensely  black.  Thirteen  days  later  the  same 
specimen  weighed  4.7453  grams.  The  fact  that  the  iron  increased  in 
weight  during  the  last  thirteen  days,  was  thought  to  indicate  the  forma- 
tion of  a  crust,  which  probably  protected  it  to  some  extent. 

104 


BROADLEAF  TRUNKS  AND  WOODS  105 

Oak  trees  commonly  require  many  years  to  reach  maturity 
but  are  then  usually  long  lived.  The  leaves  of  some  species  are 
deciduous,  while  those  of  others  are  evergreen.  Oak  trees  bear 
oblong  thin-shelled  kernels  which  protrude  from  hard  scaly  cups 
and  are  known  as  acorns.  In  the  United  States  the  woods  are 
grouped  under  three  heads  as  follows: 

The  White  Oaks. — These  woods,  which  are  more  or  less  easily  obtained, 
are  preferred  for  most  purposes.  The  principal  sources  are  White  Oak 
(Quercus  alba],  Cow  Oak  (Quercus  michauxii),  Chestnut  Oak  (Quercus 
prinus),  Post  Oak  (Quercus  minor},  Bur  Oak  (Quercus  macrocarpa), 
Pacific  Post  Oak  (Quercus  garryana). 

The  Red  or  Black  Oaks. — These  woods  are  inferior  to  the  others,  but 
are  yet  very  valuable.  The  principal  sources  are  Red  Oak  (Quercus 
rubra),  Pin  Oak  (Quercus  palustris),  Spanish  Oak  (Quercus  digitata), 
Yellow  or  Black  Oak  (Quercus  velutina) . 

The  Live  Oaks. — The  Live  Oaks,  which  are  among  the  hardest  and 
most  durable  of  all  construction  woods,  were  formerly  valued  for  ship 
building.  The  supply  is  now  limited.  The  name  is  due  to  the  " live" 
or  evergreen  leaves.  The  principal  sources  are  Live  Oak  (Quercus  vir- 
giniana},  California  Live  Oak  (Quercus  agrifolia),  Live  Oak  (Quercus 
chrysolepis) . 


1  Usually  taken  as  sub-species  or  varieties  of  the  species  Quercus  robur, 
but  thought  by  some  botanists  to  be  distinct  species,  namely,  Quercus 
pedunculata  and  Quercus  sessiliflora. 

2  Havemeyer  Chemical  Laboratory  of  New  York  University. 


106  ORGANIC  STRUCTURAL  MATERIALS 

White  Oak.  Quercus  alba  Linn. 

NOMENCLATURE. 

White  Oak  (general).  Stave  Oak  (Ark.). 

LOCALITIES. 

Widespread  throughout  north-central  and  eastern  United  States. 

FEATURES  OP  TREE. 

Seventy-five  to  one  hundred  and  fifty  feet  in  height;  three  to  six  feet  in 
diameter;  fine  shape  and  appearance;  grayish-white  bark;  compara- 
tively sweet,  ovoid,  oblong  acorns  in  rough,  shallow  cups;  the  leaves  are 
blunt,  they  are  not  bristle-tipped. 

COLOR,  GRAIN,  OR  APPEARANCE  OF  WOOD. 

Heartwood  brown  with  sapwood  lighter;  annual  layers  are  well  marked; 
medullary  rays  are  broad  and  prominent. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Tough,  strong,  heavy  and  hard;  liable  to  check  unless  seasoned  with  care; 
durable  in  contact  with  the  soil;  receives  a  high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  construction,  cooperage,  cabinet-making,  railway  ties, 
fuel,  etc.  The  bark  is  rich  in  tannin. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
50  (United  States  Forestry  Division).1 
46. 

MODULUS  OF  ELASTICITY. 

2,090,000  (average  of  218  tests  by  United  States  Forestry  Division).1 
1,380,000. 

MODULUS  OF  RUPTURE. 

13,100  (average  of  218  tests  by  United  States  Forestry  Division).1 
12,800. 

REMARKS. 

The  best  known  of  the  American  oaks.  A  tree  of  the  first  economic 
importance.  The  cellular  arrangement  of  the  wood  is  complicated, 
and,  for  this  reason,  the  wood  is  hard  to  season.  It  stands  well,  how- 
ever, after  it  has  once  been  seasoned.2 

1  See  p.  33. 

2  See  also  "White  Oak,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  106,  1907);  "The  American  White  Oak,"  Detwiler  (American  Forestry, 
January,  1916);  etc. 


BROADLEAF  TRUNKS  AND  WOODS  107 

Cow  Oak.  Quercus  michauxii  Nutt. 

NOMENCLATURE  (Sud worth). 

Cow  Oak  (local  and  common  name).     Swamp  White  Oak  (Del.,  Ala.). 
Basket  Oak   (Ala.,   Miss.,  La.,  Tex.,     Swamp  Chestnut  Oak  (Fla.). 
Ark.). 

LOCALITIES. 

Southeastern  United  States,  Delaware,  and  Florida,  westward  along  the 
Gulf  to  Texas;  also  southern  Indiana  and  Illinois  to  the  Gulf;  best  on 
rich  bottoms  in  Arkansas  and  Louisiana. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height;  three  to  six  feet  in  diameter; 
rough,  light-gray  bark  with  loose,  scaly  ridges;  the  leaves  are  only 
shallowly  toothed;  the  blunt  teeth  are  not  bristle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown;  sapwood  light-buff;  conspicuous  medullary  rays; 
close-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  very  strong,  tough,  durable,  and  easily  split. 

REPRESENTATIVE  USES  OF  WOOD. 

Construction,  agricultural  implements,  and  wheel-stock. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
46     (United  States  Forestry  Division).1 
50. 

MODULUS  OF  ELASTICITY. 

1,610,000  (average  of  256  tests  by  United  States  Forestry  Division.)1 
1,370,000. 

MODULUS  OF  RUPTURE. 

11,500  (average  of  256  tests  by  United  States  Forestry  Division).1 
15,800. 

REMARKS. 

The  principal  white  oak  of  the  Southern  States;  the  acorns  are  devoured 
by  cattle,  whence  its  name. 


1  See  p.  33. 


108  ORGANIC  STRUCTURAL  MATERIALS 

Chestnut  Oak.  Quercus  prinus  Linn. 

NOMENCLATURE  (Sudworth). 
Chestnut   Oak   (local  and  com-        Tanbark  Oak  (N.  C.). 

mon  name).  Swamp  Chestnut  Oak  (N.  C.). 

Rock  Oak  (N.  Y.,  Del.,  Pa.).  Mountain  Oak  (Ala.). 

Rock     Chestnut     Oak     (Mass., 

R.  I.,  Pa.,  Del.,  Ala.). 

LOCALITIES. 

Maine  to  Georgia,  westward  intermittently  to  Kentucky,  Tennessee,  and 
Alabama;  best  development  in  southern  Alleghany  Mountain  region. 

FEATURES  OF  TREE. 

Seventy-five  to  eighty  feet  in  height;  three  to  four  feet  in  diameter;  the 
leaves  resemble  those  of  the  Chestnut  (Castanea  dentata) ;  the  shallow 
teeth  are  not  bristle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark-brown;  sapwood  lighter;  close-grained;  conspicuous 
medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  tough,  hard,  strong,  and  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 
Largely  used  for  railway  ties,     The  bark  is  rich  in  tannin. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

46. 
MODULUS  OF  ELASTICITY. 

1,780,000. 
MODULUS  OF  RUPTURE. 

14,600. 

REMARKS.1 


1  See  also  "Chestnut  Oak,  Quercus  prinus  Linn."  (United  States  Forest 
Service, |Silvical  Leaflet,  No.  41,  1908). 


BROADLEAF  TRUNKS  AND  WOODS  109 

{Quercus  minor  Sargent 
Quercus  obtusiloba  Michx. 
Quercus  stellata  Wang 

NOMENCLATURE  (Sudworth). 

Post    Oak    (local    and    common  Overcup  Oak  (Fla.). 

name).  White  Oak  (Ky.,  Ind.). 

Iron  Oak  (Del.,  Miss.,  Neb.).  Box  Oak  (Md.) 

Box  White  Oak  (R.  I.).  Brash  Oak  (Md.). 
Chene  Stone"  (Quebec). 

LOCALITIES. 

East  of  Rocky  Mountains — Nebraska  and  the  Gulf  States,  eastward 
intermittently  to  Massachusetts  and  northern  Florida. 

FEATURES  OF  TREE. 

Fifty  to  seventy  feet  in  height;  two  to  three  feet  in  diameter;  a  low  shrub 
in  Florida;  there  are  blunt  lobes  or  projections  to  the  leaves;  the  deeply- 
cut  lobes  are  not  bristle-tipped;  the  leaves  are  clustered  at  the  ends  of 
the  branches;  a  fine  tree  with  a  rounded  top. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  or  dark  brown  with  lighter  sapwood;  close-grained; 
annual  rings  well  marked;  numerous  and  conspicuous  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  checks  badly  in  drying;  durable  in  contact  with 
the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Largely  used,  particularly  in  the  Southwest,  for  fencing,  railway  ties,  and 
fuel;  also  for  cooperage,  construction,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
50  (United  States  Forestry  Division).1 
52. 

MODULUS  OF  ELASTICITY. 

2,030,000  (average  of  49  tests  by  United  States  Forestry  Division).1 
1,180,000. 

MODULUS  OF  RUPTURE. 

12,300  (average  of  49  tests  by  United  States  Forestry  Division).1 
12,900. 

REMARKS. 

A  common  tree  in  the  Gulf  States  west  of  the  Mississippi  River.  The 
wood  of  this  species  is  seldom  distinguished  commercially  from  that  of 
white  oak. 

1  See  p.  33. 


110  ORGANIC  STRUCTURAL  MATERIALS 

Bur  Oak.  Quercus  macrocarpa  Michx. 

NOMENCLATURE  (Sudworth). 

Bur    Oak    (local    and    common  Mossycup  Oak   (Mass.,   Pa.,   Del., 

name).  Miss.,  La.,  Tex.,  Ark.,  111.,  Iowa, 

Overcup  Oak   (R.  I.,   Del.,  Pa.,  Neb.,  Kan.). 

Miss.,  La.,  111.,  Minn.).  Scrub  Oak  (Neb.,  Minn.). 

Mossycup  White  Oak  (Minn.).  Overcup  White  Oak  (Vt.). 

LOCALITIES. 

Nova  Scotia  to  Manitoba,  Wyoming,  Georgia,  and  Texas. 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  and  thirty  feet  in  height;  five  to  seven  feet  in 
diameter;  deep,  opposite  depressions  in  leaves;  the  deeply-cleft  lobes 
are  not  bristle-tipped;  this  is  the  only  Oak  yielding  structural  woods 
which  bears  acorns  with  mossy,  fringed  borders  around  their  cups; 
there  are  corky  ridges  on  the  twigs  and  young  branches. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  rich  brown;  sapwood  lighter;  close-grained;  broad,  conspicu- 
ous medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  strong,  tough,  and  very  durable  in  contact  with  the  ground. 

REPRESENTATIVE  USES  OF  WOOD. 

Similar  to  those   of  the   White   Oak    (Quercus  alba). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

46. 
MODULUS  OF  ELASTICITY. 

1,320,000. 
MODULUS  OF  RUPTURE. 

13,900. 
REMARKS. 

The  range  extends  farther  into  the  West  and  Northwest  than  that  of 
other  Eastern  oaks.  The  Bur  Oak  has  been  recommended  for  planting 
on  the  prairies.1 


xSee  also  "Bur  Oak,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  56,  1907). 


BROADLEAF  TRUNKS  AND  WOODS  111 

White  Oak.  Quercus  garryana  Douglas 

NOMENCLATURE  (Sudworth). 

White  Oak  (Cal.,  Oreg.)-  Oregon  White  Oak  (Cal.). 

Pacific  Post  Oak  (Oreg.).  California  Post  Oak. 

Western  White  Oak  (Oreg.). 

LOCALITIES. 

Pacific  Coast,  British  Columbia  into  California. 

FEATURES  OF  TREE. 

Sixty  to  ninety  feet  high;  one  and  one-half  to  two  and  one-half  feet  in 
diameter;  a  small  shrub  at  high  elevations;  the  rounded  lobes  of  the 
leaves  are  not  bristle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown  or  yellow;  sapwood  lighter,  often  nearly  white; 
compact  structure;  distinctly-marked  annual  rings;  medullary  rays 
often  conspicuous. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Heavy,  strong,  hard,  and  tough. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  carriages,  furniture,  indoor  decoration,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

46. 
MODULUS  OF  ELASTICITY. 

1,150,000. 
MODULUS  OF  RUPTURE. 

12,400. 
REMARKS. 

Locally,  this  tree  is  important.  The  best  substitute  for  Eastern  White 
Oak  produced  on  the  Pacific  Coast.1 


The  Weeping,  Valley,  Swamp,  White,  or  California  White  Oak  (Quercus 
lobata),  a  native  of  central-western  California,  is  one  of  the  largest  and  most 
symmetrical  of  all  oaks.  It  adds  to  landscapes  where  it  grows  as  the  elms 
add  to  landscapes  in  the  East.  The  brittle  wood  is  seldom  used  in  construc- 
tion, but  is  an  important  local  fuel. 

^ee  also  "Oregon  Oak,"  Graves  (United  States  Forest  Service,  Silvical 
Leaflet  No.  52,  1912). 


112  ORGANIC  STRUCTURAL  MATERIALS 

Red  Oak.  Quercus  rubra  Linn. 

NOMENCLATURE  (Sudworth). 

Red  Oak  (local  and  common  name).      Spanish  Oak  (Pa.,    N.  C.). 
Black  Oak  (Vt.,  Conn.,  N.  Y.,  Wis., 
la.,  Neb.,  So.  Dak.,  Ont.). 

LOCALITIES. 

East  of  the  Rocky  Mountains,  Nova  Scotia  to  Florida,  westward 
intermittently  to  Nebraska  and  Kansas;  best  in  Massachusetts. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  feet  in  height;  three  to  six  feet  and  over  in  diameter; 
the  brownish-gray  bark  is  smooth  on  the  branches;  the  leaves  have 
sharp-pointed,  bristle-tipped  lobes;  there  are  relatively  small  acorns 
in  flat,  shallow  cups;  a  fine,  complete  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown  or  red;  sapwood  lighter;  coarse-grained;  well- 
marked  annual  rings;  medullary  rays  few,  but  broad, 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  inclined  to  check  in  drying;  acid;  red  oak  is 
inferior  to  white  oak. 

REPRESENTATIVE  USES  OF  WOOD. 

Works  of  secondary  importance,  clapboards,  cooperage,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
45  (United  States  Forestry  Division).1 
40. 

MODULUS  OF  ELASTICITY. 

1,970,000  (average  of  57  tests  by  United  States  Forestry  Division).1 
1,600,000. 

MODULUS  OF  RUPTURE. 

11,400  (average  of  57  tests  by  United  States  Forestry  Division).1 
14,000. 

REMARKS. 

The  Red  Oak  grows  more  rapidly  than  other  oaks.  The  bark  is  used  in 
tanning. 


1  See  p.  33. 


BROADLEAF  TRUNKS  AND  WOODS  113 

Pin  Oak.  Quercus  palustris 

NOMNECLATURE  (Sudworth).  Water  Oak  (R.  I.,  111.). 

Pin    Oak    (local    and    common         Swamp  Oak  (Pa.,  Ohio,  Kans.), 

name). 
Swamp      Spanish      Oak      (Ark.,         Water  Spanish  Oak  (Ark.). 

Kan.). 

LOCALITIES. 

Massachusetts,  Michigan,  and  Missouri,  southward  to  Virginia,  Ten- 
nessee, and  Oklahoma. 

FEATURES  OF  TREE. 

Fifty  to  eighty  feet  in  height;  two  to  four  feet  in  diameter;  a  full-rounded 
or  pyramidal  top;  the  bark  is  thin  and  smooth ;  there  are  numerous  small, 
pin-like  branches;  the  leaves  are  deeply-cleft;  their  lobes  are  bristle- 
tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  variegated  light-brown;  sap  wood  nearly  white;  coarse-grained; 
medullary  rays  numerous  and  conspicuous. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  checks  badly  in  seasoning. 

REPRESENTATIVE  USES  OF  WOOD. 

Shingles,  clapboards,  construction,  interior  finish,  and  cooperage. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

43. 
MODULUS  OF  ELASTICITY. 

1,500,000. 
MODULUS  OF  RUPTURE. 

15,400. 
REMARKS. 

The  numerous  slender,  secondary  branches  suggest  pins  and  cause  the  tree 
to  be  easily  recognized,  even  in  winter. 


114  ORGANIC  STRUCTURAL  MATERIALS 

(  Quercus  digitata  Sudworth 

Spanish  Oak.  \  Quercus  falcata  Michx. 

(  Quercus  triloba 

NOMENCLATURE  (Sudworth). 

Spanish  Oak  (local  and  common  name). 

Red  Oak  (N.  C.,  Va.,  Ga.,  Fla.,  Ala.,  Miss.,  La.,  Ind.). 

LOCALITIES. 

New  Jersey  and  Florida,  westward  intermittently  to  Illinois  and  Texas; 
most  abundant  in  the  Gulf  States. 

FEATURES  OF  TREE. 

Thirty  to  seventy  feet  in  height;  two  and  one-half  to  four  feet  in  diameter; 
variable  foliage;  the  deeply-cleft,  sharp-pointed  leaves  are  bristle- 
tipped;  the  acorns  are  globular  to  oblong. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-red;  sap  wood  lighter;  coarse-grained;  the  annual  layers 
are  strongly  marked;  the  medullary  rays  are  few,  but  conspicuous. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  and  strong;  not  durable;  checks  badly  in  drying. 

REPRESENTATIVE  USES  OF  WOOD. 

Somewhat  used  for  cooperage,  construction,  etc.  The  bark  is  very  rich  in 
tannin. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

43. 
MODULUS  OF  ELASTICITY. 

1,900,000. 
MODULUS  OF  RUPTURE. 

16,900. 
REMARKS. 

Grows  rapidly,  often  on  dry,  barren  soil. 


BROADLEAF  TRUNKS  AND  WOODS  115 

I  Quercus  velutina  Lam. 
Black  Oak,  Yellow  Oak.  | 


NOMENCLATURE  (Sudworth). 

Black   Oak,    Yellow   Oak    (local  Tanbark  Oak  (111.). 

and  common  names).  Spotted  Oak  (Mo.). 

Yellow   Bark,   Yellow-bark   Oak  Quercitron  Oak  (Del.,   S.  C.,  La., 

(R.I.,  Minn.).  Kans.,  Minn.). 
Dyer's  Oak  (Tex.). 

LOCALITIES. 

East  of  longitude  96  degrees;  Maine  and  Florida,  westward  intermittently 
to  Minnesota  and  Texas;  best  in  North-  Atlantic  States. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  and  thirty  feet  in  height;  three  to  five  feet  in  diam- 
eter; dark-gray  to  black  bark;  yellow  inner  bark;  the  acorns  have  bitter, 
yellow  kernels;  the  foliage  turns  handsomely  in  the  autumn;  the  sharply- 
cleft  leaves  are  bristle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  reddish-brown;  sapwood  lighter;  coarse-grained;  the 
annual  layers  are  strongly  marked;  the  medullary  rays  are  thin. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  liable  to  check  in  drying;  not  tough. 

REPRESENTATIVE  USES  OF  WOOD. 

Cooperage,  construction,  furniture,  and  decoration. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
45  (United  States  Forestry  Division).1 
44. 

MODULUS  OF  ELASTICITY. 

1,740,  000  (average  of  40  tests  by  United  States  Forestry  Division).1 
1,470,000. 

MODULUS  OF  RUPTURE. 

10,800  (average  of  40  tests  by  United  States  Forestry  Division).1 
14,800. 

REMARKS. 

The  yellow  inner  bark  affords  a  yellow  dye 


See  p.  33. 


116  ORGANIC  STRUCTURAL  MATERIALS 

Liv    Oak  ^  Quercus  virginiana  Mill. 

\  Quercus  virens  Ait. 

NOMENCLATURE  (Sudworth). 

Live  Oak  (Va.,  N.  C.,  S.  C.,  Ga.,         Chene  Vert  (La.). 
Fla.,    Miss.,    Ala.,    Tex.,    La., 
Gal.). 

LOCALITIES. 

Atlantic  Coast  from  Virginia  to  Florida,  westward  to  Texas  and  Lower 
California;  southern  Mexico,  Central  America,  and  Cuba;  a  Southern 
species;  grows  best  in  South- Atlantic  States. 

FEATURES  OF  TREE. 

Fifty  to  sixty  feet  in  height;  three  to  six  feet  in  diameter;  general  resem- 
blance to  the  Apple-tree;  evergreen  foliage;  the  oblong,  blunt  leaves  are 
not  bristle-tipped. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown  or  yellow;  sap  wood  nearly  white;  close-grained; 
compact  structure;  the  medullary  rays  are  pronounced;  the  annual 
layers  are  often  hardly  distinguishable. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  strong,  tough,  and  hard;  difficult  to  work;  splits  easily;  receives 
a  high  polish;  very  durable. 

REPRESENTATIVE  USES  OF  WOOD. 
Ship-building. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

59. 
MODULUS  OF  ELASTICITY. 

1,600,000. 
MODULUS  OF  RUPTURE. 

14,000. 
REMARKS. 

The  trunks  and  branches  furnish  small,  straight  pieces,  but  the  principal 
yield  is  in  knees  and  crooked  or  compass  timbers.  The  wood  splits  so 
easily  that  it  is  often  fastened  with  bolts  or  trenails,  rather  than  with 
spikes.  The  trees,  which  are  now  scarce,  grow  rapidly. 


BROADLEAF  TRUNKS  AND  WOODS  117 

California  Live  Oak.  Quercus  agrifolia  Nee 

NOMENCLATURE  (Sudworth). 

Coast  Live  Oak  (Cal.).  Encena  (Gal.). 

California  Live  Oak  (Cal.).  Evergreen  Oak  (Cal.). 

LOCALITIES. 

California  and  Lower  California. 

FEATURES  OF  TREE. 

Forty  to  seventy-five  and  occasionally  more  feet  in  height;  three  to  six 
feet  in  diameter;  evergreen  foliage;  the  leaves  are  spiked  like  those  of 
the  Holly;  the  shape  resembles  that  of  the  Apple-tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  creamy-white,  darkens  on  exposure;  compact  structure;  the 
annual  layers  are  hardly  distinguishable. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Heavy  and  hard,  but  brittle. 

REPRESENTATIVE  USES  OF  WOOD. 
Fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

61. 

MODULUS  OF  ELASTICITY. 

1,350,000. 
MODULUS  OF  RUPTURE. 

13,200. 
REMARKS. 


118  ORGANIC  STRUCTURAL  MATERIALS 

Live  Oak.  Quercus  chrysolepis  Liebm. 

NOMENCLATURE  (Sudworth). 

Live  Oak  (Cal.,  Oreg.).  Canyon  Oak,  Iron  Oak,  Maul  Oak, 

Canyon   Live   Oak,    Black   Live         Valparaiso  Oak  (Cal.). 
Oak,  Golden-cup  Oak  (Cal.). 

LOCALITIES. 

West  of  the  Rocky  Mountains,  in  canyons  and  at  high  elevations. 

FEATURES  OF  TREE. 

Fifty  to  eighty  feet  in  height;  three  to  six  feet  in  diameter;  often  a  low 
shrub;  impressive  appearance;  evergreen  foliage;  some  leaves  have 
smooth,  thickened  margins,  but  occasionally  leaves  have  spiny-toothed 
margins. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown;  sap  wood  lighter;  there  are  small  pores  in  the 
wide  bands  that  are  parallel  to  the  conspicuous  medullary  rays;  close- 
grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  strong,  tough,  and  difficult  to  work. 

REPRESENTATIVE  USES  OF  WOOD. 

Implements,  wagons,  and  tool-handles. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

52. 
MODULUS  OF  ELASTICITY. 

1,700,000. 
MODULUS  OF  RUPTURE. 

18,000. 
REMARKS. 

Said  to  be  the  most  valuable  of  the  California  oaks.  Grows  at  eleva- 
tions of  two  thousand  to  five  thousand  feet.  The  Highland  Live  Oak 
(Quercus  wislizeni)  is  an  evergreen  tree  which  also  grows  on  the  Pacific 
Coast.  The  Highland  Live  Oak  differs  from  the  Live  Oak  (Quercus 
chrysolepis)  in  the  fact  that  the  leaves  of  the  former  are  always  spiny- 
toothed. 


BROADLEAF  TRUNKS  AND  WOODS  119 

English  Oak.  Quercus  robur  var.  pedunculata 

NOMENCLATURE. 

English  Oak.  Common  Oak. 

British  Oak. 

LOCALITIES. 

Widespread  throughout  northern  and  central  Europe. 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  feet  in  height;  three  to  five  feet  in  diameter; 
the  branches  are  crooked,  the  leaves  stalkless,  and  the  acorns  long-stalked. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown,  darker  spots  frequent;  sap  wood  lighter;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  tough,  strong,  and  durable;  difficult  to  work;  liable  to  warp  in 
seasoning. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  beams,  and  cabinet-work;  used  formerly  in  carpentry. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
51  (Laslett). 

MODULUS  OF  ELASTICITY. 
1,170,000  (Thurston). 

MODULUS  OF  RUPTURE. 
10,000  (Thurston). 

REMARKS. 

The  English,  Chestnut,  Durmast,  or  Red  Oak  (Quercus  robur  var.  ses- 
siliflora),  which  is  distinguished  from  the  English  Oak  (Quercus  robur 
var.  pedunculata)1  by  its  long  leafstalks  and  its  short  acorn  stalks, 
yields  a  similar  but  lower-rated  wood.  These  two  trees  supply  the 
"British  Oak"  of  commerce.  Dantzic,  Rigi,  and  some  other  European 
oaks  are  in  all  probability  really  English  Oaks,  which  are  named  from 
the  ports  from  which  they  are  shipped.  Durmast  Oak  (Quercus  pubes- 
cens  or  Quercus  robur  intermedia)  is  not  as  common  as  the  English  Oak 
(Quercus  robur  var.  pedunculata)  with  which  it  is  often  confused. 
Laslett  states  that  it  is  often  hard  to  distinguish  one  of  these  woods 
from  another  without  tracing  the  logs  back  to  their  original  sources. 
Early  authorities  advised  that  these  woods,  which  contain  much  gallic 
acid,  should  not  be  fastened  with  iron;  but  the  woods  are  now  better 
seasoned,  and,  as  stated  before,  oak  woods  are  now  safely  fastened  with 
iron,  at  least  in  the  United  States. 


1  As  stated,  these  two  trees  are  usually  assumed  to  be  sub-species  or  varie- 
ties of  the  species  Quercus  robur.  But  by  some  they  are  believed  to  be  dis- 
tinct species,  that  is,  Quercus  pedunculata  and  Quercus  sessiliflora. 


ASH 

Fraxinus 

These  trees  grow  in  many  places  in  the  temperate  regions  of 
the  northern  hemisphere. 

The  wood  resembles  oak  in  many  particulars,  but  is  coarser, 
lighter,  easier  to  work,  tougher,  more  elastic,  and  less  attractive 
than  oak.  Ash  seasons  well,  but  does  not  last  well  when  exposed 
to  the  weather.  It  is  used  for  stairs,  furniture,  and  some  of  the 
cheaper  forms  of  cabinet  work.  Second-growth  ash  is  tougher 
and  more  pliable  than  first-growth  ash.1 

Ash  woods  are  often  grouped  under  two  heads:  White  Ash 
includes  the  lighter  colored  and  more  desirable  pieces,  while 
Black  Ash  includes- the  darker  and  inferior  woods.  This  prac- 
tical division  agrees  with  the  botanical  division  in  the  North, 
since  in  the  North  the  only  notable  species  are  White  Ash 
(Fraxinus  americana)  and  Black  Ash  (Fraxinus  nigra).  The 
wood  of  the  Green  Ash  (Fraxinus  lanceolata)  of  the  south  is 
usually  classed  as  White  Ash.  One-half  of  the  thirty-nine  known 
species  of  the  genus  Fraxinus  are  natives  of  North  America.2 


1  Trees  that  grow  up  after  virgin  forests  are  cut  away  afford  what  are 
known  as  " second-growth  woods."     Ordinarily,  second-growth  woods  are 
inferior  to  first-growth  woods,  because  second-growth  woods,  being  younger, 
have  more  sapwood.     In  this  case  it  is  the  sapwood  that  is  often  preferred. 

2  See  also  "The  Ashes:  Their  Characteristics  and  Management,"  Sterrett 
(United  States  Department  of  Agriculture,  Bulletin  No.  299). 

120 


BROADLEAF  TRUNKS  AND  WOODS  121 

White  Ash.  Fraxinus  americana  Linn. 

NOMENCLATURE  (Sudworth). 

White  Ash    (local  and   common         Cane  Ash  (Ala.,  Miss.,  La.). 

name).  American  Ash  (la.). 

Ash   (Ark.,   la.,   Wis.,   111.,   Mo., 
Minn.). 

LOCALITIES. 

Nova  Scotia  to  Florida,  westward  intermittently  to  Minnesota  and  Texas; 
greatest  development  in  the  Ohio  River  basin. 

FEATURES  OF  TREE. 

Forty-five  to  ninety  feet  in  height,  occasionally  higher;  three  to  four  feet 
in  diameter;  the  dark-brown  or  gray-tinged  bark  is  deeply  divided  by 
narrow  fissures  into  broad,  flattened  ridges;  the  seeds  have  long  wings. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  reddish-brown,  usually  mottled;  sapwood  much  lighter,  some- 
times nearly  white;  coarse-grained;  compact  structure;  the  layers  are 
clearly  marked  by  large,  open  ducts;  the  medullary  rays  are  often 
obscure. 

STRUCTURAL  QUALITIES  OP  WOOD. 

Heavy,  hard,  strong,  and  elastic,  becoming  brittle  with  age;  not  durable  in 
contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Agricultural  implements,  carriages,  handles,  oars,  interior  and  cheap 
cabinet-work. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
39  (United  States  Forestry  Division).1 
40. 

MODULUS  OF  ELASTICITY. 

1,640,000  (average  of  87  tests  by  United  States  Forestry  Division).1 
1,440,000. 

MODULUS  OP  RUPTURE. 

10,800  (average  of  87  tests  by  United  States  Forestry  Division).1 
12,200. 

REMARKS. 

These  valuable  trees  grow  rapidly,  particularly  when  on  low,  rather  moist 
soil.  They  are  not  apt  to  form  forests,  but  are  usually  found  in  clumps 
or  mingled  with  trees  of  other  species.  Large  trees  sometimes  have 
large  heart-cracks.  The  trees  are  also  subject  to  a  fungus  disease  which 
reduces  the  wood  to  a  useless,  soft,  pulpy,  yellowish  mass.  This  dis- 
ease, which  is  known  as  white  rot,  progresses  until  the  tree  becomes  so 
weak  that  it  is  blown  over  by  the  winds.  The  disease  does  not  attack 
dead  or  seasoned  woods.  See  also  von  Schrenk  (United  States  Bureau 
of  Plant  Industry,  Bulletin  No.  32.) 

lSee  p.  33. 


122  ORGANIC  STRUCTURAL  MATERIALS 

-; 

Red  Ash  <  ^nmrms  pennsylvanica  Marsh 

\  Fraxinus  pubescens  Lam. 

NOMENCLATURE  (Sudworth). 

Red    Ash    (local    and    common  Brown  Ash  (Mo.). 

name).  Black  Ash  (N.  J.). 

River  Ash  (R.  I.,  Ont.).  Ash  (Neb.). 

LOCALITIES. 

New  Brunswick  to  Florida,  westward  intermittently  to  the  Dakotas  and 
Alabama;  best  developed  in  the  North- Atlantic  States. 

FEATURES  OF  TREE. 

Rarely  much  over  forty-five  feet  in  height  and  about  one  foot  in  diameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood   rich  brown;   sapwood   light  brown,  streaked   with   yellow; 
coarse-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Heavy  and  hard;  strong,  but  brittle. 

REPRESENTATIVE  USES  OF  WOOD. 

Agricultural  implements,  handles,  boats,  oars,  and  paper-pulp. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

38. 
MODULUS  OF  ELASTICITY. 

1,154,000. 
MODULUS  OF  RUPTURE. 

12,300. 
REMARKS. 

Grows  on  borders  of  streams  and  swamps,  in  low,  rich  soil. 


BROADLEAF  TRUNKS  AND  WOODS  123 

Blue  Ash.  Fraxinus  quadrangulata  Michx. 

NOMENCLATURE  (Sudworth). 

Blue  Ash  (Mich.,  111.,  Ky.,  Mo.,  Ala.). 

LOCALITIES. 

Ontario  and  Minnesota,  southward  to  Tennessee,  Alabama,  and  Arkansas. 

FEATURES  OF  TREE. 

Fifty  to  seventy-five  feet  in  height,  occasionally  higher;  one  to  two  feet 
in  diameter;  a  slender  tree;  blue  properties  in  inner  bark;  smooth, 
square  twigs;  leaves  composed  of  seven  to  eleven  pointed,  rough- 
margined  leaflets. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  yellow,  streaked  with  brown;  sapwood  lighter;  close- 
grained;  compact  structure;  satin-like  appearance. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard  and  heavy,  but  brittle;  not  strong;  the  most  durable  of  the  Ash 
woods. 

REPRESENTATIVE  USES  OF  WOOD. 

Largely  used  in  flooring,  carriage-building,  pitchfork  and  other  tool- 
handles. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

44. 
MODULUS  OF  ELASTICITY. 

1,100,000. 
MODULUS  OF  RUPTURE. 

11,500. 
REMARKS. 

Blue  Ash  trees  grow  best  on  limestone  formations.  The  inner  bark  con- 
tains properties  which  give  water  a  bluish  tint.  Blue  Ash  has  no  supe- 
rior among  the  Ash  woods.  Blue  Ash  pitchfork-handles  are  highly 
prized. 


124  ORGANIC  STRUCTURAL  MATERIALS 

\  Fraxinus  niqra  Marsh 
Black  Ash.  v«      •  »     •*  i-    r 

( Fraxinus  samoucifoha  Lam. 

NOMENCLATURE  (Sudworth). 

Black   Ash    (local  and   common        Swamp  Ash  (Vt.,  R.  I.,  N.  Y.). 

name).  Brown  Ash  (N.  H.,  Tenn.). 

Water  Ash  (W.  Va.,  Tenn.,  Ind.).         Hoop  Ash  (Vt.,  N.  Y.,  Del.,  Ohio, 

111.,  Ind.). 
LOCALITIES. 

Newfoundland,  through  Canada  to  Manitoba,  southward  to  Illinois, 
Missouri,  and  Arkansas. 

FEATURES  OF  TREE. 

Seventy  to  eighty  feet  in  height;  one  to  one  and  one-half  feet  in  diameter; 
a  thin  tree;  excrescences  or  knobs  are  frequent  on  trunks;  dark,  almost 
black,  winter  buds. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  dark  brown;  sapwood  light  brown,  often  nearly  white;  coarse- 
grained; compact  structure;  the  medullary  rays  are  numerous  and  thin. 

STRUCTURAL  QUALITIES  OP  WOOD. 

Separates  easily  in  layers;  rather  soft  and  heavy,  tough,  and  elastic;  not 
strong  or  durable  when  exposed. 

REPRESENTATIVE  USES  OP  WOOD. 

Largely  used  for  interior  finish,  fencing,  barrel-hoops,  cabinet-making, 
splint  baskets,  an4  chair-bottoms. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

39. 
MODULUS  OF  ELASTICITY. 

1,230,000. 
MODULUS  OF  RUPTURE. 

11,400. 
REMARKS. 

The  Black  Ash  is  found  farther  north  than  other  Ash  trees.  It  is  one  of 
the  most  slender  of  trees.  The  distorted  grain  in  the  excrescences, 
knobs,  or  burls,  causes  the  wood  from  such  burls  to  be  prized  for 
veneers. 


BROADLEAF  TRUNKS  AND  WOODS  125 

f  Fraxinus  lanceolata  Borkh. 
Green  Ash.  I  Fraxinus  viridis  Michx.  f. 

(  Fraxinus  pennsylvanica  var .  lanceolata  Sarg. 

NOMENCLATURE  (Sud  worth). 

Green  Ash    (local  and   common         Ash  (Ark.,  Iowa). 

name).  Swamp  Ash  (Fla.,  Ala.,  Tex.). 

Blue  Ash  (Ark.,  Iowa).  Water  Ash  (Iowa). 

White  Ash  (Kans.,  Neb.). 

LOCALITIES. 

East  of  the  Rocky  Mountains — Vermont  and  northern  Florida,  inter- 
mittently to  Utah  and  Arizona. 

FEATURES  OF  TREE. 

Forty  to  fifty  feet  in  height;  one  to  two  feet  in  diameter;  the  upper  and 
lower  surfaces  of  the  smooth  leaves  are  bright  green. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish,  sap  wood  lighter;  rather  coarse-grained;  compact 

structure. 
STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  and  strong,  but  brittle. 

REPRESENTATIVE  USES  OF  WOOD. 

Similar  to  those  of  White  Ash  (Fraxinus  americana). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
39  (United  States  Forestry  Division).1 
44. 

MODULUS  OF  ELASTICITY. 

2,050,000  (average  of  10  tests  by  United  States  Forestry  Division).1 
1,280,000. 

MODULUS  OF  RUPTURE. 

11,600  (average  of  10  tests  by  United  States  Forestry  Division.)1 
12,700. 

REMARKS. 

Sometimes  considered  a  variety  of  Red  Ash  (Fraxinus  pennsylvanica). 


1  See  p.  33. 


126  ORGANIC  STRUCTURAL  MATERIALS 

Oregon  Ash.  Fraxinus  oregona  Nutt. 

NOMENCLATURE. 

Oregon  Ash  (Gal.,  Wash.,  Oregon). 

LOCALITIES. 

Pacific  Coast,  British  Columbia  to  southern  California. 

FEATURES  OF  TREE. 

Fifty  to  occasionally  seventy-five  feet  in  height;  one  to  one  and  one-half 
feet  in  diameter;  the  dark  grayish-brown  bark  exfoliates  in  thin  scales. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brown;  sap  wood  lighter;  coarse-grained;  compact  structure; 
there  are  numerous  thin  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Rather  light  and  hard,  but  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Furniture,  carriage-frames,  cooperage,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

35. 
MODULUS  OF  ELASTICITY. 

1,200,000. 
MODULUS  OF  RUPTURE. 

9,400. 
REMARKS. 

One  of  the  valuable  deciduous  trees  of  the  Pacific  Coast.     Thrives  only 
on  moist  soils  and  in  moist  climates. 


The  Toothache  Trees  (Xanthoxylum  americana  and  Xanthoxylum  dava- 
herculis)  are  known  as  Ash  and  Prickly  Ash.  The  Gopher  Wood  (Cladrastis 
tinctoria)  is  Yellow  Ash.  These  woods  are  not  important. 

The  name  "Mountain  Ash"  is  applied  to  several  species  (Sorbus 
americana  and  Sorbus  sambucifolia)  that  yield  bright  red  berries  and 
soft,  light,  close-grained,  practically  valueless  woods.  The  trees  are 
related  to  the  apple. 


BROADLEAF  TRUNKS  AND  WOODS  127 

Most  trees  that  yield  edible  fruits  are  valued  for  the  fruits,  and  are 
not  normally  cut  in  large  quantities  for  wood. 

The  Apple  (Pyrus  mains) .  These  trees  originated  in  Europe,  but  are 
now  common  in  all  temperate  climates.  They  are  seldom  much  over 
thirty  feet  in  height,  and  normally  afford  hard,  heavy,  close-grained, 
brittle  woods,  that  are  liable  to  warp  during  seasoning.  The  woods  are 
suitable  for  implements  and  tool  handles.  Many  varieties  of  Apple 
have  been  perfected  by  cultivation.1 

The  Sweet  or  American  Crab  Apple  Trees  (Pyrus  coronaria)  grow  in 
many  places  from  Massachusetts  and  Nebraska  southward  to  Georgia 
and  Texas.  The  trees  are  seldom  more  than  twenty-five  feet  in  height 
and  one  foot  in  diameter.  The  hard,  close-grained  wood  is  occasionally 
used  in  turnery.  The  trees  are  prized  in  landscape  effects  because  of 
their  sweet-scented  blossoms. 

The  Oregon  Crab  Apple  (Pyrus  rivularis)  grows  on  the  Pacific  Coast 
from  California  to  Alaska  and  sometimes  attains  a  height  of  forty  feet. 
The  fine,  hard,  heavy,  close-grained  woods  are  used  for  mallets  and  tool 
handles.  The  Narrowleaf  Crab  Apple  (Pyrus  augustifolia)  yields  a 
similar  wood. 

The  Pear  (Pyrus  communis)  is  widely  cultivated  in  many  regions  with 
temperate  climates.  The  wood,  which  is  rather  hard  and  heavy,  is  so 
firm,  fine,  tough,  and  close-grained  that  it  has  been  used  for  type,  draw- 
ing squares,  and  triangles.  It  is  used  in  turnery  and  occasionally  in 
furniture.  Many  varieties  have  been  obtained  by  cultivation. 

The  Orange  (several  species,  as  Citrus  aurantium  and  Citrus  trifoliatd) 
was  introduced  into  the  West  Indies,  Florida,  Louisiana,  and  California 
from  Asia  and  the  shores  of  the  Mediterranean.  The  small  trees  bear 
oily,  partially  evergreen  leaves,  fragrant  flowers,  and  edible  fruit,  which 
with  oils  and  essences  are  highly  prized.  The  strong,  hard,  heavy,  close- 
grained,  lemon-colored  wood  is  cut  into  souvenirs  and  other  small  ob- 
jects. A  piece  of  American  Orange  wood,  exhibited  at  the  St.  Louis 
Exposition,  was  ten  inches  wide.  Many  varieties  of  Orange  trees  have 
been  obtained  by  cultivation. 

The  Olive  (Olea  europcea). — Olive  trees  were  introduced  into  southern 
California  from  Asia  and  the  shores  of  the  Mediterranean  by  the  early 
Spanish  missionaries.  The  irregularly  formed  trees,  from  thirty  to 
forty  feet  in  height,  bear  evergreen  leaves  and  valuable  oily  fruit.  The 
mottled,  rich  orange-brown,  hard,  heavy,  close-grained  heartwood  of 
foreign  trees  is  prized  for  inlaid  work,  small  objects,  and  souvenirs. 
The  heartwood  of  the  older  trees  is  the  best.  American  Olive  wood  is 
not  particularly  attractive  because  the  heartwood  has  not  yet  had  time 
to  mature  sufficiently.  Many  varieties  of  Olive  trees  have  been  obtained 
by  cultivation. 

1  "The  Apples  of  New  York, "  Beach,  Booth  and  Taylor  (New  York  State 
Department  of  Agriculture). 


ELM 
Ulmus 

The  several  species  of  Elm  are  distributed  over  the  eastern 
and  central  portions  of  the  United  States.  Elm  trees  are  prized 
for  their  fine  form  and  appearance.  Because  they  have  no  lower 
branches,  they  are  particularly  good  for  planting  along  streets 
and  near  houses.  Elm  trees  attain  a  high  degree  of  perfection 
in  some  parts  of  New  England. 

Elm  wood  is  tough,  fibrous,  durable,  strong,  hard,  heavy,  and 
difficult  to  split  and  work.  It  stands  well  against  shocks,  and, 
for  this  reason,  piles  of  Elm  are  useful  in  ferry  slips.  The  grain 
arrangement  is  often  attractive,  and  the  wood  is  sometimes  used 
in  less  important  kinds  of  cabinet  work.  It  is  characteristically 
employed  in  piles,  flumes,  wagons,  cars,  agricultural  implements, 
and  machinery.  The  tall,  straight  trunks  yield  pieces  of  con- 
siderable size.  The  wood  is  used  in  naval  construction  from 
parts  of  the  largest  ships  to  canoes  where  it  enters  the  lattice 
upon  which  occupants  sit  or  place  their  feet.  Elm  is  also  used 
for  carriages  upon  which  heavy  cannon  are  mounted.  It  is 
used  in  cooperage,  floors,  pump  handles,  and  trunks.  The  bark 
of  the  elm  tree  was  used  by  the  Indians  in  canoes  and  for  rope. 

The  tree  is  easily  recognized  by  its  form.  Fifteen  or  sixteen 
species  are  known  to  exist.1 


1  See  also   "The  American  Elm/'    Detwiler    (American  Forestry,  May, 
1916). 

128 


BROADLEAF  TRUNKS  AND  WOODS  129 

White  Elm.  Ulmus  americana  Linn. 

NOMENCLATURE  (Sudworth). 

White    Elm    (local    and    common  Pa.,  N.  C.,  S.  C.,  la.,  Wis.). 

name).  American  Elm  (Vt.,    Mass.,  R.  I., 

Water  Elm  (Miss.,  Tex.,  Ark.,  Mo.,  N.   Y.,  Del.,  Pa.,   N.  C.,   Miss., 

111.,  la.,  Mich.,  Minn.,  Neb.).  Tex.,   III.,    Ohio,     Kans.,    Neb., 

Elm    (Mass.,  R.  I.,   Conn.,  N.  J.,  Mich.,  Minn.). 

LOCALITIES. 

East  of  the  Rocky  Mountains,  Newfoundland  to  Florida,  westward 
intermittently  to  the  Dakotas,  Nebraska,  and  Texas. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  feet  in  height;  three  to  seven  feet  in  diameter;  a 
characteristic  and  beautiful  form;  smooth  buds;  the  leaves,  which  are 
smaller  than  those  of  the  Slippery  Elm  (Ulmus  pubescens),  are  rough 
only  when  rubbed  one  way. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  light  brown;  sap  wood  yellowish  white;  rather  coarse-grained; 
annual  rings  clearly  marked. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong,  tough,  fibrous,  and  difficult  to  split. 

REPRESENTATIVE  USES  OF  WOOD. 

Flooring,  wheel-stock,  barrel  staves,  ship-building,  flumes,  and  piles.1 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
34  (United  States  Forestry  Division).2 
40. 

MODULUS  OF  ELASTICITY. 

1,540,000  (average  of  18  tests  by  United  States  Forestry  Division).2 
1,060,000. 

MODULUS  OF  RUPTURE. 

10,300  (average  of  18  tests  by  United  States  Forestry  Division).2 
12,100. 

REMARKS. 

The  concentration  of  the  foliage  at  the  top,  together  with  their  pleasing 
form,  renders  these  trees  valuable  in  landscape  effects.  Elm  trees  do 
not  cause  dense  shade.  Elm  trees  and  Silver  Maple  trees  are  among 
the  first  to  show  life  in  the  spring.  At  that  time,  discarded  brown- 
ish scales  cover  the  ground  in  the  vicinity  of  the  trees. 

1  See  also  "White  Elm,"  Pinchot  (United  States  Forest  Service,  Circular 
No.    66,   1907);    "The   American    Elm,"    Detwiler    (American    Forestry, 
May,  1916). 

2  See  page  33. 


130  ORGANIC  STRUCTURAL  MATERIALS 

~    .  „!  /  Ulmus  racemosa  Thomas 

Cork  Elm.  s  TT7  .  _ 

I  Ulmus  thomasi  Sarg. 

NOMENCLATURE  (Sudworth). 

Cork   Elm    (local   and   common       Rock  Elm  (R.  I.,  W.  Va.,  Ky.,  Mo. 

name).  111.,  Wis.,  la.,  Mich.,  Neb.). 

Hickory  Elm  (Mo.,  111.,  Ind.,  la.).         White  Elm  (Ont.). 

Cliff  Elm  (Wis.). 
LOCALITIES. 

Quebec,  Ontario,  Michigan,  and  Wisconsin,  southward  to  Connecticut, 
northern  New  Jersey,  Ohio,  Missouri,  and  eastern  Nebraska. 

FEATURES  OF  TREE. 

Seventy  to  ninety  feet  in  height;  two  to  three  feet  in  diameter;  thick, 
corky,  irregular  projections  give  the  bark  a  characteristic,  shaggy 
appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown,  often  tinged  with  red;  sapwood  yellowish  or 
greenish  white;  compact  structure;  the  fibers  interlace. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  very  strong,  tough,  elastic,  and  difficult  to  split;  receives  a 
beautiful  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Heavy  agricultural  implements,  wheel-stock,  barrel  staves,  railway  ties, 
sills,  bridge-timbers,  axe-helves,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

45. 
MODULUS  OF  ELASTICITY. 

2,550,000. 
MODULUS  OF  RUPTURE. 

15,100. 
REMARKS. 
This  is  the  best  of  the  Elm  woods. 


BROADLEAF  TRUNKS  AND  WOODS  131 

_       _t  f  Ulmus  pubescens  Walt. 

Slippery  Elm,  Red  Elm.  <  r,7        ^  ,      ,,.  , 

I  Ulmus  fulva  Michx. 

NOMENCLATURE  (Sudworth). 

Slippery  Elm,  Red  Elm  (local  and         Redwooded  Elm  (Term.), 
common  names).  Moose  Elm  (occasional). 

Rock  Elm  (Tenn.). 

LOCALITIES. 

Ontario  and  Florida,  westward  intermittently  to  Nebraska  and  Texas; 
best  developed  in  the  Western  States. 

FEATURES  OF  TREE. 

Forty-five  to  sixty  feet  in  height;  one  to  two  feet  in  diameter;  characteristic 
form;  mucilaginous  inner  bark;  the  buds  are  hairy;  the  leaves  are 
rough  when  rubbed  either  way. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark  brown  or  red;  sapwood  lighter;  compact  structure;  the 
annual  layers  are  marked  by  rows  of  large,  open  ducts;  heartwood 
greatly  preponderates. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Heavy,  hard,  strong,  and  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Largely  used  for  fence-posts,  rails,  barrel  staves,  railway  ties,  sills,  sleigh- 
runners,  and  wheel-stock ;  the  mucilaginous  bark  is  employed  in  medicine. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

43. 
MODULUS  OF  ELASTICITY. 

1,300,000. 
MODULUS  OF  RUPTURE. 

12,300. 
REMARKS. 


132  ORGANIC  STRUCTURAL  MATERIALS 

Wing  Elm,  Winged  Elm.  Ulmus  alata  Michx. 

NOMENCLATURE.  Mountain    Elm,    Red    Elm    (Fla., 
Wing  Elm,   Winged  Elm   (local  Ark.). 

and  common  names).  Elm,  Witch  Elm  (W.  Va.). 

Wahoo,  Whahoo  fW.  Va.,  N.  C.,  Water  Elm  (Ala.). 

S.  C.,  La.,  Tex.,  Ky.,  Mo.).  Small-leaved  Elm  (N.  C.). 

Cork    Elm,    Corky    Elm    (Fla.,  Wahoo  Elm  (Mo.). 

S.  C.,  Tex.). 

LOCALITIES. 

Southern  United  States,  Virginia,  and  Florida,  westward  intermittently  to 
southern  Illinois  and  Texas. 

FEATURES  OF  TREE. 

Forty  feet  or  more  in  height;  one  to  two  feet  in  diameter;  there  are  corky 
"wings"  on  the  branches;  the  smooth  leaves  are  smaller  than  those  of 
the  White  Elm  (Ulmus  americand). 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  brownish;  sapwood  lighter;  close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Hard,  heavy,  tough,  and  fibrous. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

46. 
MODULUS  OF  ELASTICITY. 

740,000. 
MODULUS  OF  RUPTURE. 

10,200. 
REMARKS. 

Not  a  very  common  tree. 


MAPLE 

Acer 

Maple  trees  grow  on  all  the  northern  continents.  Nearly  one- 
half  of  the  known  species  are  native  to  Asia.  The  principal 
European  species  (Acer  pseudo-platanus)  is  known  in  Europe  as  a 
Sycamore.  The  Hard  or  Sugar  Maple  (Acer  saccharum)  is  one 
of  the  principal  deciduous  trees  of  North  America.1 

Maple  wood  is  noted  for  its  attractive  appearance  and  its  fine, 
compact  structure.  Its  appearance  is  so  attractive  that  selected 
pieces  are  classed  with  the  most  beautiful  of  the  cabinet  woods, 
and  its  structure  is  so  fine  and  compact  that  it  is  sometimes  used 
for  carvings  and  even  for  type.  Birdseye  Maple  and  Curly 
Maple  are  not  separate  species,  but  are  results  of  cellular  distor- 
tions that  may  occur,  in  some  form,  on  other  trees  as  well  as 
Maples.  Birdseye  and  blister  effects  are  most  often  seen  in  the 
wood  of  the  Hard  Maple  (Acer  saccharum),  while  curly  effects 
are  most  often  seen  in  the  Soft  Maples.  It  is  usually  impossible 
to  tell  definitely  how  the  woods  are  figured  until  the  bark  is 
removed  or  the  trees  are  cut.  Maple  wood  is  tough  and  strong. 
It  shrinks  moderately  and  stands  well  in  protected  places,  but 
is  not  durable  when  exposed.  It  is  used  for  flooring,  panelling, 
furniture,  school  supplies,  implements,  machinery,  and  shoe- 
lasts.  Sugar  is  separated  from  the  sap  of  the  Sugar  Maple. 

The  Boxelder  (Acer  negundo)  is  a  true  Maple.  The  trees  are 
very  beautiful,  and,  like  other  Maple  trees,  are  valued  for  orna- 
mental purposes.  The  soft,  light  wood  is  occasionally  used  for 
woodenware,  interior  finish,  and  paper  pulp.  Small  quantities 
of  sugar  are  present  in  the  sap  of  this  tree. 

Maple  trees  bear  two-seeded  fruit  or  "keys;"  the  parts  of 
these  keys  spread  differently  in  different  species.  The  leaves  of 
some  species  change  from  green  to  red  and  other  brilliant  colors  in 
the  autumn.  Sixty  to  seventy  species  have  been  distinguished. 
Nine  of  these  are  native  to  North  America. 

1  See  also  "Beech,  Birches  and  Maples,"  Maxwell  (United  States  Depart- 
ment of  Agriculture  Bulletin  No.  12,  1913:) 

133 


134  ORGANIC  STRUCTURAL  MATERIALS 

(  Acer  saccharum  Marsh 
Sugar  Maple.  Hard  Maple.  T     .         TT. 

I  Acer  sacchannum  Wang 

NOMENCLATURE  (Sudworth). 

Sugar  Maple,  Hard  Maple  (local  Rock    Maple    (Me.,    Vt.,    N.    H., 

and  common  names).  Conn.,     Mass.,    R.    I.,    N.    Y., 

Black  Maple  (Fla.,  KyM  N.  C.).  Tenn.,    111.,    Mich.,     la.,     Kan., 

Sugar  Tree  (frequent).  Wis.,  Minn.). 

» 

LOCALITIES. 

Best  development  Newfoundland  to  Manitoba.  Range  extends  south- 
ward to  Florida  and  Texas. 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  or  more  feet  in  height;  one  and  one-half  to  four 
feet  in  diameter;  the  flowers  appear  with  the  leaves  in  the  spring;  the 
fruit  or  "maple-keys,"  with  wings  less  than  at  right  angles,  ripen  in  the 
early  autumn;  one  seed-cavity  in  each  is  usually  empty;  the  leaves 
exhibit  brilliant  reds  and  other  colors  in  the  autumn ;  a  large,  impressive 
tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish;  sap  wood  lighter;  close-grained;  compact  structure; 
occasional  curly,  blister,  or  birdseye  effects. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Tough,  heavy,  hard,  strong,  and  receives  a  good  polish;  wears  evenly; 
not  durable  when  exposed. 

REPRESENTATIVE  USES  OF  WOOD. 

Furniture,  shoe-lasts,  piano-actions,  wooden  type  for  showbills,  pegs 
interior  finish,  flooring,  ship-keels,  vehicles,  fuel,  veneers,  rails,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

43. 
MODULUS  OF  ELASTICITY. 

2,070,000. 
MODULUS  OF  RUPTURE. 

16,300. 

REMARKS.1 


1  See  also  "Sugar  Maple,  Acer  saccharum  Marsh"  (United  States  Forest 
Service,  Silvical  Leaflet  No.  42,  1908).  "The  Sugar  Maple,"  Detwiler 
(American  Forestry,  November,  1915). 


BROADLEAF  TRUNKS  AND  WOODS  135 

/  Acer  saccharinum  Linn. 

Silver  Maple,  Soft  Maple.  ,  „, 

I  Acer  dasycarpum  E,hr. 

NOMENCLATURE  (Sud worth). 

Silver  Maple,  Soft  Maple  (local  White  Maple  (Me.,  Vt.,  R.  I.,  N.  Y., 

common  names).  N.  J.,  Pa.,  W.  Va.,  N.  C.,  S.  C., 

Swamp  Maple  (W.  Va.,  Md.).  Ga.,  Ma.,  Ala.,  Miss.,  La.,  Ky., 

Water  Maple  (Pa.,  W.  Va.).  Mo.,     111.,     Ind.,     Kans.,    Neb., 

River  Maple  (Me.,.N.  H.,  R.  I.,  Minn.). 

W.  Va.,  Minn.).' 

LOCALITIES. 

New  Brunswick  to  Florida,  westward  intermittently  to  the  Dakotas  and 
Oklahama;  best  development  in  lower  Ohio  River  basin. 

FEATURES  OF  TREE. 

Forty  to  ninety  feet  in  height,  occasionally  higher;  three  to  five  feet  in 
diameter;  fine  form,  sometimes  suggesting  that  of  the  Elm;  the  maple- 
keys,  with  long,  stiff,  more  than  right-angled  wings,  ripen  in  the  early 
summer;  the  flowers  appear  before  the  leaves  in  the  spring;  the  leaves 
exhibit  yellows,  but  seldom  reds,  in  the  autumn. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish  brown;  sapwood  ivory  white;  fine-grained;  compact 
structure;  the  fibers  are  sometimes  twisted,  waved,  or  " curly." 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  brittle,  easily  worked,  and  moderately  strong;  receives  a  high  polish; 
not  durable  when  exposed  to  the  weather. 

REPRESENTATIVE  USES  OF  WOOD. 

Woodenware,  turned  work,  interior  decoration,  flooring,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

32. 
MODULUS  OF  ELASTICITY. 

1,570,000. 
MODULUS  OF  RUPTURE. 

14,400. 
REMARKS. 

Waving,  spiral,  or  curly  figures  are  pronounced  in  the  woods  of  this  species. 

Resemblances  to  light  and  shadows  are  particularly  real  on  planed 

surfaces. 


136  ORGANIC  STRUCTURAL  MATERIALS 

Red  Maple,  Swamp  Maple.  Acer  rubrum  Linn- 

NOMENCLATURE  (Sudworth). 

Red  Maple,  Swamp  Maple  (local  Water  Maple  (Miss.,  La.,  Tex.,  Ky., 

and  common  names).  Mo.). 

Soft  Maple  (Vt.,  Mass.,  N.  Y.,  White  Maple  (Me.,  N.  H.). 

Va.,  Miss.,  Mo.,  Kans.,  Neb.,  Red  Flower  (N.  Y.). 

Minn.). 

LOCALITIES. 

New  Brunswick  and  Florida,  westward  intermittently  to  the  Dakotas 
and  Texas.  Wide  range. 

FEATURES  OF  TREE. 

Sixty  to  eighty  feet  and  more  in  height;  two  and  one-half  to  four  feet  in 
diameter;  red  twigs  and  flowers  appear  before  the  leaves  in  the  early 
spring. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brown,  tinged  with  red;  sapwood  lighter;  close-grained; 
compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  elastic,  but  not  strong;  easily  worked. 

REPRESENTATIVE  USES  OF  WOOD. 

Largely  used  in  cabinet-making,  turnery,  woodenware,  and  gun-stocks. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

38. 
MODULUS  OF  ELASTICITY. 

1,340,000. 
MODULUS  OF  RUPTURE. 

15,000. 
REMARKS. 

The  wood  occasionally  shows  a  "curly  figure." 


BROADLEAF  TRUNKS  AND  WOODS  137 

Oregon  Maple.  Acer  macrophyllum  Pursh. 

NOMENCLATURE  (Sudworth). 

Oregon  Maple  (Oreg.,  Wash.).  Broad-leaved  Maple  (Central  CalM 

White  Maple  (Oreg.,  Wash.).  Willamette  Valley,  Ore.). 

Maple  (Cal.). 

LOCALITIES. 

Alaska  to  California;  best  in  rich  bottom  lands  of  southern  Oregon. 

FEATURES  OF  TREE. 

Seventy  to  one  hundred  feet  in  height;  three  to  five  feet  in  diameter; 
beautiful  appearance;  pendant  clusters  of  flowers  appear  after  the  leaves 
in  the  spring. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish  brown;  sapwood  whitish;  close-grained;  compact 
structure;  occasionally  figured. 

STRUCTURAL  QUALITIES. 
Light,  hard,  and  strong;  receives  a  high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Locally  used  for  tool-handles,  turned  work,  and  furniture. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

30. 
MODULUS  OF  ELASTICITY. 

1,100,000. 
MODULUS  OF  RUPTURE. 

9,720. 
REMARKS. 
This  ornamental  tree  has  been  introduced  into  Europe.1 


also  "Manual  Trees  of  North  America,"  Sargent,  p.  628. 


138  ORGANIC  STRUCTURAL  MATERIALS 


Bozelder,  Ash-leaved  Maple.  ^ 

I  Negundo  aceroides  Moench. 

NOMENCLATURE  (Sudworth). 

Boxelder,       Ash-leaved      Maple  Stinking  Ash  (S.  C.). 

(local  and  common  names).  Negundo  Mapie  (HI.). 

Red    River    Maple,    Water   Ash  Three-leaved  Maple  (Fla.). 

(Dak.).  Black  Ash  (Term.). 

Cut-leaved  Maple  (Colo.).  Sugar  Ash  (Fla.). 

LOCALITIES. 

Atlantic  Ocean,  westward  intermittently  to  Rocky  Mountains  and 
Mexico. 

FEATURES  OP  TREE. 

Forty  to  seventy  feet  in  height;  one  and  one-half  to  three  feet  in  diameter; 
the  wings  to  the  keys  are  straight  or  incurved;  the  leaves  exhibit  yel- 
lows, but  seldom  reds,  in  the  autumn;  the  flowers  appear  with  or  before 
the  leaves  in  the  spring. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thin  heartwood,  cream  white;  sapwood  similar;  close-grained;  compact 
structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  soft;  not  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Woodenware,  cooperage,  paper-pulp,  and  occasionally  interior  finish. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

26. 
MODULUS  OF  ELASTICITY. 

82,000. 
MODULUS  OF  RUPTURE. 

7,500. 
REMARKS. 

The  Boxelders  withstand  severe  climatic  changes,  grow  rapidly  and  are 
good  trees  to  plant  in  many  otherwise  treeless  sections.  Sugar  is 
sometimes  obtained  from  the  sap  of  this  species.  See  also  "Boxelder" 
(United  States  Forest  Service  Circular  No.  86). 


WALNUT 

Juglans 

The  English  or  Royal  Walnut  (Juglans  regia)  is  the  principal 
species  in  Europe,  while  the  Black  Walnut  (Juglans  nigrd),  and 
the  Butternut  or  White  Walnut  (Juglans  tinerea)  grow  in  the 
United  States.  Botanically,  Circassian  Walnut  is  the  same  as 
English,  Royal,  or  European  Walnut.  English  Walnut  is  the 
name  used  almost  exclusively  by  those  who  grow  the  tree  for  its 
nuts,  while  Circassian  Walnut  is  the  name  usually  applied  to  the 
wood.1 

The  English  Walnut  was  introduced  from  Asia  into  Greece  and 
Italy,  and,  through  these  countries,  into  others.  It  is  cultivated 
in  the  United  States,  but  principally  for  its  nuts.  The  appear- 
ance and  desirability  of  the  wood  differ  with  localities.  Pieces 
cut  from  English  trees  are  said  to  be  paler  and  coarser  than  those 
cut  from  Italian  and  French  trees.  Ordinary  pieces  exhibit 
large  open  figures,  with  waves  and  streaks  of  gray  and  yellowish- 
white,  while  exceptional  excrescences  known  as  burrs,  which  are 
sometimes  two  or  three  feet  across,  yield  figured  woods  of  great 
beauty.  Circassian  Walnut  is  very  valuable,  and  is  now  used 
almost  exclusively  in  costly  decorations,  piano  cases,  and  high- 
grade  furniture.  No  other  wood  is  better  for  gun-stocks,  and, 
until  the  battle  of  Waterlo,  othe  demand  in  Europe  for  this  pur- 
pose was  so  great  that  as  much  as  six  hundred  pounds  sterling 
is  said  to  have  been  paid  for  a  single  tree. 

At  the  present  time  (1917)  the  supply  of  Black  Walnut  for  making 
stocks  for  military  rifles  is  ample.  A  manufacturer  writes  as  follows: 
"At  the  beginning  of  the  great  war  (1914)  we  were  under  the  im- 
pression that  we  might  experience  some  difficulty  in  securing  sufficient 
of  this  wood;  but  we  have  had  no  such  trouble,  in  fact,  we  have  had 
much  more  of  it  offered  to  us  than  we  require." 

American  or  Black  Walnut  was  once  very  popular,  in  the 
United  States,  as  a  cabinet  wood.  The  trees  are  now  scarce; 
lighter  colored  Woods  are  preferred,  and,  at  present,  walnut  is 
seldom  seen  save  in  gun-stocks  and  old  furniture.  The  figures 
that  characterize  pieces  of  Circassian  Walnut  are  absent  in  the 

139 


140  ORGANIC  STRUCTURAL  MATERIALS 

darker,  more  uniformly  tinted  American  woods.  Black  Walnut 
trees  seldom  form  forests  by  themselves,  but  are  usually  found 
mixed  with  those  of  other  species.  They  grow  rapidly,  but  the 
valuable  heartwood  does  not  mature  until  a  number  of  years 
after  the  trees  have  been  planted. 

Small  pieces  of  dark,  rich  brown  wood  are  obtained  from  the 
Mexican  or  Arizona  Walnut  (Juglans  rupestris),  which  grows  in 
some  of  the  sparsely  settled  regions  of  the  Southwest,  where  it  is 
also  known  as  the  Western,  Dwarf,  Little,  and  California  Walnut. 
The  true  California  Walnut  (Juglan  calif  or  nica)  is  found  on  the 
Pacific  Coast  from  the  Sacramento  River  to  the  San  Bernardino 
Mountains,  and  sometimes  attains  diameters  of  fifteen  inches. 
The  blue-brown  woods  can  be,  but  seldom  are,  used  in  cabinet 
making.  The  White  Walnut  or  Butternut  (Juglans  cinerea)  yields 
a  rather  soft,  light,  grayish-brown  heartwood  that  is  sometimes 
used  in  cabinet  making. 

Walnut  trees  may  be  known  by  their  nuts.  The  husks  or 
pods  are  not  quartered  as  in  the  case  of  the  hickories. 


1  "Circassian  Walnut,"  Sudworth  and  Mell  (United  States  Forest  Service, 
Circular  No.  212). 


BROADLEAF  TRUNKS  AND  WOODS  141 

Circassian  Walnut,  European  Walnut.  Juglans  regia 

NOMENCLATURE  (Sudworth  and  Mell). 

Circassian  Walnut,  European  Walnut,  Russian  Walnut. 

English  Walnut,  Royal  Walnut  (local  Turkish  Walnut. 

and  common  names).  Nogal     (Spain,     Cuba,     and 

Persian  Walnut.  South  America). 

French  Walnut.  Ancona  Auvergne  (Italy). 

Italian  Walnut.  Noyer  (France). 

Austrian  Walnut.  • 

LOCALITIES. 

Widely  planted  on  all  of  the  continents. 

FEATURES  OF  TREE. 

About  40  feet  in  height;  attractive  in  appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  dark  chocolate  brown,  tints  sometimes  extending  from  light 
brown  to  black;  sapwood  lighter;  beautiful  veins  and  figures,  particularly 
in  the  wood  of  older  trees;  fine,  close  grain. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Moderately  hard,  moderately  heavy;  splits  but  little  in  seasoning;  the 
sapwood  is  liable  to  become  worm-eaten. 

REPRESENTATIVE  USES  OF  WOOD. 

Circassian  Walnut  was  formerly  used  in  turnery,  toys,  carved  work, 
carpentry,  wooden  shoes,  and  gun-stocks.  The  wood  is  now  scarce 
and  is  only  employed  in  the  most  costly  furniture  and  cabinet  work. 

WEIGHTS  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
MODULUS  OF  ELASTICITY. 
MODULUS  OF  RUPTURE. 

REMARKS. 

For  many  years  the  demands  for  this  wood  have  been  greater  than  the 
supply.  Among  the  related  woods  which  have  been  used  as  substi- 
tutes are  the  Caucasian  Walnut  (Pterocarya  caucasica)1,  the  West 
Indian  Walnut  (Juglans  insularis),  the  Nogal  (Juglans  australis),  and 
the  Butternut  (Juglans  cinered).  The  Red  Gum  (Liquidambar  styra- 
ciflua),  which  is  sometimes  called  the  Satin  Walnut,  is  often  handsomely 
veined,  and  is  then  very  similar  to  true  Circassian  Walnut. 

1  The  similarity  of  names  is  such  that  Caucasian  Walnut  and  Circassian 
Walnut  are  sometimes  confused  with  one  another.  The  wood  of  the  former 
lacks  the  veining  which  characterizes  the  latter. 


142  ORGANIC  STRUCTURAL  MATERIALS 

Black  Walnut.  Juglans  nigra  Linn. 

NOMENCLATURE  (Sudworth). 

Black  Walnut  (local  and  common  name).  Walnut  (N.  Y.,  Del.,  W.  Va., 

Fla.,  Ky.,  Mo.,  Ohio,  Ind.,  la.). 
LOCALITIES. 

Ontario  and  Florida,  westward  intermittently  to  Nebraska  and  Texas. 

FEATURES  OP  TREE. 

Ninety  to  one  hundred  and  twenty-five  feet  in  height;  three  to  eight  feet 
in  diameter;  a  tall,  handsome  tree  with  rough,  brownish,  almost  black, 
bark ;  the  compound  leaves  are  composed  of  from  thirteen  to  twenty- 
three  leaflets;  the  nuts  are  large  and  rough-shelled. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  rich,  dark,  chocolate  brown;  the  thin  sapwood  is  much  lighter 
in  color;  rather  coarse-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  strong,  easily  worked,  and  durable;  receives  a  high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Cabinet-making  and  gun-stocks;  also  formerly  furniture  and  decoration. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

38. 
MODULUS  OF  ELASTICITY. 

1,550,000. 
MODULUS  OF  RUPTURE. 

12,100. 
REMARKS. 

This  tree  is  now  somewhat  rare  in  the  Eastern  parts  of  the  United  States.1 


See  also  "Handbook  Trees  of  Northern  States  and  Canada,"  Hough. 


BROADLEAF  TRUNKS  AND  WOODS  143 

Butternut,  White  Walnut.  Juglans  cinerea  Linn. 

NOMENCLATURE. 

Butternut,  White  Walnut   (local         Walnut  (Minn.). 

and  common  names).  White  Mahogany. 

Oil  Nut  (Me.,.  N.  H.,  S.  C.). 

LOCALITIES. 

New  Brunswick  to  Georgia,  westward  to  Dakota  and  Arkansas;  best  in 
Ohio  River  basin. 

FEATURES  OP  TREE. 

Medium  size,  sometimes  seventy-five  feet  or  over  in  height;  two  to  four 
feet  in  diameter;  the  branches  are  widespread;  the  compound  leaves  a  re 
composed  of  from  eleven  to  seventeen  leaflets;  there  are  large-sized, 
oblong,  edible  nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  gray-brown,  darkening  with  exposure;  sapwood  nearly 
white;  coarse-grained;  compact  structure;  an  attractive  wood. 

STRUCTURAL  QUALITIES  OP  WOOD. 

Light,  soft,  and  easily  worked,  but  not  strong;  receives  a  high  polish. 

REPRESENTATIVE  USES  OP  WOOD. 

Interior  finish  and  cabinet-work.     The  inner  bark  furnishes  a  yellow  dye. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

25. 
MODULUS  OF  ELASTICITY. 

1,150,000. 
MODULUS  OP  RUPTURE. 

8,400. 

REMARKS.1 


also  "Handbook  Trees  of  Northern  States  and  Canada,"  Hough. 


HICKORY 

Hicoria 

The  Hickories  grow  in  the  temperate  regions  of  eastern  North 
America,  and  eastern  Asia. 

The  woods,  which  are  noted  for  strength,  toughness,  flexibility, 
and  resilience,  are  used  for  handles,  implements,  machinery 
and  carriage  parts.  Axe  handles  and  hammer  handles  of  this 
wood  have  no  superiors.  The  reputation  of  American  axes  and 
hammers  owes  much  to  the  qualities  of  these  handles.  The 
properties  that  render  Hickory  valuable  are  most  pronounced  in 
the  sapwood,  which,  in  this  species,  is  more  desirable  than  the 
heartwood.  Second  growth  Hickory  is  prized,  since,  being 
younger,  it  contains  more  of  the  pliable  sapwood.  Hickory  does 
not  last  well  in  exposed  positions. 

The  genus  includes  about  a  dozen  species.  The  Hickories 
may  be  distinguished  from  the  Walnuts  by  the  nuts.  In  most 
cases,  the  nuts  of  the  Hickories  are  covered  with  husks  that 
divide  into  four  parts,  while  those'  of  the  Walnuts  remain  un- 
broken.1 


1  See  also  "The  Commercial  Hickories,"  Boisen  and  Newlin  (United 
States  Forest  Service,  Bulletin  No.  80,  1910);  "Manufacture  and  Utiliza- 
tion of  Hickory,"  Hatch  (United  States  Forest  Service,  Circular  No.  187, 
1911). 

144 


BROADLEAF  TRUNKS  AND  WOODS  145 

f  Hicoria  ovata  Mill. 
Shagbark  ttckory,  Shellbaik  Hackory,          ( 


Shagbark. 

NOMENCLATURE  (Sudworth). 

Shagbark  or  Shellbark  Hickory  Hickory  (Vt.,  Ohio). 

(local  and  common  names).  Upland  Hickory  (111.). 

Scalybark  Hickory  (W.  Va.,  S.  C.,  White  Hickory  (la.,  Ark.). 

Ala.).  Walnut  (Vt.,  N.  Y.). 

Shellbark  (R.  I.,  N.  Y.,  Pa.,  N.  C.).  Sweet  Walnut  (Vt.). 

Shagbark  (R.  I.,  Ohio).  Shagbark  Walnut  (Vt.). 

LOCALITIES. 

Quebec  to  Florida,  westward  intermittently  to  Minnesota  and  Texas. 
Wide  range,  best  in  Ohio  Valley. 

FEATURES  OP  TREE. 

Seventy-five  to  ninety  feet  in  height,  occasionally  higher;  two  and  one- 
half  to  three  feet  in  diameter;  shaggy  bark;  the  compound  leaves  are 
composed  of  five  and,  rarely,  seven  leaflets;  there  are  thin-shelled, 
edible  nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown;  sapwood  ivory  white  or  cream  colored;  close- 
grained;  compact  structure;  the  annual  rings  are  clearly  marked;  the 
medullary  rays  are  numerous  but  thin. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Very  heavy,  very  hard,  strong,  exceptionally  tough  and  flexible;  not 
durable  when  exposed. 

REPRESENTATIVE  USES  OF  WOOD. 

Largely  used  for  agricultural  implements,  wheels,  runners,  axe  handles, 
baskets,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
51  (United  States  .Forestry  Division).1 
52. 

MODULUS  OF  ELASTICITY. 

2,390,000  (average  of  137  tests  by  United  States  Forestry  Division).1 
1,900,000. 

MODULUS  OF  RUPTURE. 

16,000  (average  of  137  tests  by  United  States  Forestry  Division).1 
17,000. 

REMARKS. 

The  nuts  form  an  important  article  of  commerce.  "Shagbark"  refers  to 
the  shaggy  appearance  of  the  bark.2 

1  See  p.  33. 

2  See  also  "Shagbark  Hickory"  (United  States  Forest  Service,  Circular 
No.  62,  1907). 


146  ORGANIC  STRUCTURAL  MATERIALS 

Pignut.  Hicoria  glabra  Mill. 

Gary  a  porcina  Nutt. 

NOMENCLATURE  (Sudworth). 

Pignut  (local  and  common  name).  White  Hickory  (N.  H.,  la.). 

Black  Hickory  (Miss.,  La.,  Ark.,  Broom  Hickory  (Mo.). 

Mo.,  Ind.,  la.).  Hardshell  (W.  Va.). 

Brown     Hickory     (Del.,     Miss.,  Red  Hickory  (Del.). 

Tex.,  Tenn.,  Minn.).  Switchbud  Hickory  (Ala.). 
Bitternut  (Ark.,  111.,  la.,  Wis.). 

LOCALITIES. 

Maine  to  Florida,  westward  intermittently  to  southern  Nebraska  and 
eastern  Texas. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height,  occasionally  higher;  two  to 
four  feet  in  diameter;  rather  smooth  bark;  the  compound  leaves  are 
composed  of  from  three  to  seven  leaflets;  the  large,  thick-shelled  nuts 
contain  kernels  that  are  often  astringent  or  bitter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  and  dark  brown;  the  thick  sapwood  is  lighter;  close- 
grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  flexible,  tough,  and  strong. 

REPRESENTATIVE  USES  OF  WOOD. 
Similar  to  those  of  Shagbark  Hickory  (Hicoria  ovata). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
56  (United  States  Forestry  Division).1 
51. 

MODULUS  OF  ELASTICITY. 

2,730,000  (average  of  30  tests  by  United  States  Forestry  Division.)1 
1,460,000. 

MODULUS  OF  RUPTURE. 

18,700  (average  of  30  tests  by  United  States  Forestry  Division.)1 
14,800. 

REMARKS.2 

1  See  p.  33. 

2  See  also  "Pignut  Hickory,    Hicoria  glabra    (Mill.)"    Britton    (United 

States  Forest  Service,  Silvical  Leaflet  No.  48,  1909). 


BROADLEAF  TRUNKS  AND  WOODS  147 

f  Hicoria  alba  Linn. 
Mocker  Nut.  j  Carya  tomentosa  NuiL 

NOMENCLATURE  (Sudworth). 

Mocker  Nut,    Whiteheart  Hick-  Big-bud,  Red  Hickory  (Fla.). 

ory  (local  and  common  names).  Common  Hickory  (N.  C.). 

Bullnut     (N.     Y.,     Fla.,     Miss.,  White  Hickory  (Pa.,  S.  C.). 

Tex.,  Mo.,  Ohio,  111.,  Minn.).  Hickory  Nut  (Ky.,  W.  Va.). 

Black  Hickory  (Tex.,  Miss.,  La.,  Hog  Nut  (Del.). 

Mo.).  Hard  bark  Hickory  (111.). 
Hickory    (Ala.,  Tex.,  Pa.,  S.  C., 

Neb.). 

LOCALITIES. 

Ontario  to  Florida,  westward  intermittently  to  Missouri  and  Texas. 
Wide  range. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height;  two  and  one-half  to  three  and 
one-half  feet  in  diameter;  a  tall,  slender  tree  with  rough,  but  not  shaggy, 
bark;  the  compound  leaves  are  composed  of  from  five  to  nine  leaflets; 
there  are  thick-shelled,  edible  nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  rich,  dark  brown;  the  thick  sapwood  is  nearly  white;  close- 
grained. 

STRUCTURAL  QUALITIES  OP  WOOD. 

Very  heavy,  hard,  tough,  strong,  and  flexible. 

REPRESENTATIVE  USES  OP  WOOD. 
Similar  to  those  of  Shagbark  Hickory  (Hicoria  ovata). 

WEIGHT  OP  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
53  (United  States  Forestry  Division).1 
51. 

MODULUS  OF  ELASTICITY. 

2,320,000  (average  of  75  tests  by  United  States  Forestry  Division).1 
1,630,000. 

MODULUS  OP  RUPTURE. 

15,200  (average  of  75  tests  by  United  States  Forestry  Division).1 
16,000. 

REMARKS. 

The  most  generally  distributed  species  of  the  genus  in  the  South 


1  See  p.  33. 


148  ORGANIC  STRUCTURAL  MATERIALS 

p  /  Hicoria  pecan  Marsh 

I  Carya  olivceformis  Nutt. 

NOMENCLATURE  (Sud worth). 

Pecan  (local  and  common  name). 
Pecan  Nut,  Pecan-tree,  Pecanier  (La.). 

LOCALITIES. 

Valley  of  Mississippi,  southward  to  Louisiana  and  Texas. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  feet  in  height,  sometimes  higher;  two  and  one-half 
to  five  feet  in  diameter;  a  tall  tree;  the  compound  leaves  are  composed  of 
from  nine  to  fifteen  leaflets;  there  are  smooth-shelled,  oblong,  edible 
nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light-brown,  tinged  with  red;  sapwood  lighter  brown;  close- 
grained  and  compact;  the  medullary  rays  are  numerous,  but  thin. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy  and  hard,  but  not  strong  and  brittle. 

REPRESENTATIVE  USES  OF  WOOD. 
Fuel;  seldom  used  in  construction. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
49  (United  States  Forestry  Division).1 
44. 

MODULUS  OF  ELASTICITY. 

2,530,000  (average  of  37  tests  by  United  States  Forestry  Division).1 
940,000. 

MODULUS  OF  RUPTURE. 

15,300  (average  of  37  tests  by  United  States  Forestry  Division).1 
8,200. 

REMARKS. 

Grows  on  borders  of  streams  in  low,  rich  soil.  It  is  the  largest  and  most 
important  tree  of  Western  Texas.  The  sweet,  edible  nuts  form  an 
important  article  of  commerce. 

1  See  p.  33. 


CHESTNUT,  CHINQUAPIN 

Castanea 

These  trees  grow  in  many  parts  of  eastern  North  America, 
southern  Europe,  northern  Africa,  western  Asia,  and  parts  of 
China  and  Japan. 

European  Chestnut  wood  was  once  held  in  high  regard.  It 
should  be  noted,  however,  that  some  of  the  constructions,  in 
which  this  wood  was  thought  to  exist,  were  actually  built  of  oak. 
The  wood  of  the  North  American  Chestnut  (Castanea  vulgaris), 
which  is  weak,  brittle,  easily  worked,  and  very  durable,  is  one  of 
the  best  of  those  used  for  fence  posts,  and  mud  sills,  where  dura- 
bility rather  than  great  strength  is  required.  Hough  mentions  a 
Chestnut  fence-rail  that  was  good  after  having  been  exposed  for 
about  one  hundred  years. 

The  chestnut  bark  disease  now  tentatively  named  Diaporthe  para- 
sitica  Murrill1  was  first  detected  in  New  York  City  parks  in  1904. 
Seventeen  thousand  trees  soon  succumbed  in  one  park  alone  (Forest 
Park,  Brooklyn).  The  disease,  which  was  probably  introduced  from 
Japan,  is  conveyed  by  winds  and  insects,  and  no  tree  once  attacked 
ever  recovers.  The  value  of  the  trees  thus  far  destroyed  is  very  great 
and  the  prospective  losses  are  enormous.2 

The  name  Chinquapin  applies  to  two  North  American  species : 
the  Common  Chinquapin  (Castanea  pumila)  grows  in  the  Central 
and  Southeastern  States;  while  the  Western,  Goldenleaf,  or 
California  Chinquapin,  or  "Evergreen  Chestnut,"  (Castanopsis 
chrysophylla)  grows  on  the  Pacific  Coast.  Both  of  these  species 
afford  woods  that  resemble  ordinary  chestnut. 

The  American  Chestnut  (Castanea  vulgaris)  is  known  by  its 
large,  prickly  burrs  that  contain  from  one  to  three  thin-shelled, 
triangular,  wedge-shaped,  edible  nuts.  The  Chinquapins  bear 
prickly  burrs  that  hold  one,  or  occasionally  two,  sweet  edible 
nuts. 


1  Some  botanists  believe  that  this  blight  is  Endothia  gyrosa,  while  others 
characterize  it  as  Endothia  gyrosa  var.  parasitica. 

2  See  also  Journal  of  New  York  Botanical  Garden  (Vol.  II,  p.  143) ;  also, 
Marlatt  (National  Geographic  Magazine,  April,  1911);  "Report  of  Chest- 
nut  Tree   Blight,"    Mickleborough    (Pennsylvania   State   Department   of 
Forestry);  etc. 

149 


150  ORGANIC  STRUCTURAL  MATERIALS 

(Castanea  dentata  (Marsh)  Borkh. 
Castanea  vesca  var.  americana  Michx. 
Castanea  vulgaris  var.  americana  A.  de  C. 
NOMENCLATURE. 

Chestnut  (local  and  common  name). 

LOCALITIES. 

New  England,  Ontario,  and  New  York  to  Georgia,  Alabama,  and  Missis- 
sippi; also  Kentucky,  Missouri,  and  Michigan ;  best  on  the  Western  slope 
of  the  Alleghany  Mountains. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height;  five  to  twelve  feet  in  diameter ; 
a  fine,  characteristic  shape,  not  easily  distinguished  from  that  of  the 
Red  Oak  (Quercus  rubra)  in  winter;  the  trees  blossom  in  midsummer; 
the  prickly  burrs  contain  three,  exceptionally  five,  thin-shelled  nuts.1 

COLOR,  APPEARANCE  OR  GRAIN  OF  WOOD. 

Heart  wood  brown;  sap  wood  lighter;  coarse-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light  and  soft;  not  strong;  liable  to  check  and  warp  in  drying;  easily  split; 
very  durable  in  exposed  positions. 

REPRESENTATIVE  USES  OF  WOOD. 

Cabinet-making,  railway  ties,  posts,  fencing,  and  sills. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,200,000. 
MODULUS  OF  RUPTURE. 

9,800. 
REMARKS. 
In  the  eastern  part  of  the  United  States,  chestnut  trees  have  been  attacked 

by  a  fungus  (tentatively  named  Diaporthe  parasitica),2  which  (1913) 

is  apparently  destroying  all  of  the  chestnut  forests. 

1  See  also  "Chestnut,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  71,   1907);    "The    American    Chestnut    Tree,"    Detwiler    (American 
Forestry,  October,  19 15);  etc. 

2  As  stated  elsewhere,  some  botanists  believe  that  this  blight  should  be 
characterized  as  Endothia  gyrosa  or  Endothia  gyrosa  var.  parasitica. 


BROADLEAF  TRUNKS  AND  WOODS  151 

Chinquapin.  Castanea  pumila  (Linn.}  Mill. 

NOMENCLATURE  (Sudworth). 

Chinquapin  (Del.,  N.  J.,  Pa.,  Va.,  W.  Va.,  N.  C.,  S.  C.,  Ga.,  Ala.,  Fla., 
Miss.,  La.,  Tex.,  Ark.,  Ohio,  Ky.,  Mo.,  Mich.). 

LOCALITIES. 

Pennsylvania  and  New  Jersey  to  Florida,  Mississippi,  Louisiana,  Texas, 
Arkansas,  Ohio,  Kentucky,  Missouri,  and  Michigan. 

FEATURES  OF  TREE. 

A  small  tree,  sometimes  forty-five  feet  in  height;  one  to  two  feet  or  over 
in  diameter;  sometimes  a  low  shrub;  can  be  distinguished  from  the 
Chestnut  (Castanea  dentata}  by  the  fact  that  the  leaves  are  smooth  on 
both  sides;  the  small,  prickly  burrs  contain  single,  small  chestnut-col- 
ored nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark  brown;  sapwood  hardly  distinguishable;  coarse-grained; 
the  annual  layers  are  marked  by  rows  of  open  ducts. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Rather  heavy,  hard,  and  strong;  durable  in  exposed  positions;  liable  to 
check  in  drying. 

REPRESENTATIVE  USES  OF  WOOD. 
Posts,  rails,  railway  ties,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

36. 
MODULUS  OF  ELASTICITY. 

1,620,000. 
MODULUS  OF  RUPTURE. 

14,000. 
REMARKS. 

This  tree  is  more  suitable  for  planting  in  parks  than  as  a  source  of  lumber. 


The  Chinquapin  (Castanopsis  chrysophylla}  is  a  tree  with  characteristics 
which  are  between  those  of  the  Oak  and  Chestnut.  Its  wood,  which  is  nearly 
similar  to  that  of  the  Chinquapin  (Castanea  pumila},  is  sometimes  used  for 
implements.  It  is  native  in  Oregon  and  California. 


BEECH 

Fagus 

The  Beeches  are  represented  in  the  temperate  regions  of  the 
northern  hemisphere  by  a  single  species  (Fagus  americana).  The 
European  Beech  (Fagus  sylvatica)  is  an  important  tree  abroad.1 

Beech  wood  is  hard,  heavy,  strong,  fine-grained,  not  durable 
when  exposed,  and  somewhat  subject  to  attack  by  insects. 
European  Beech  is  employed  to  a  considerable  extent  in  construc- 
tion and  turnery,  and  is  used  more  than  almost  any  other  local 
wood  for  fuel.  Beech  possesses  almost  all  of  the  properties  that 
are  valued  in  construction,  save  durability  in  exposed  positions; 
in  Europe,  this  deficiency  is  corrected  by  artificial  means.  Beech 
responds  more  completely  than  Oak  to  treatment  with  anti- 
septics, and  the  French  secure  longer  service  from  many  treated 
Beech  ties,  than  Americans  secure  from  many  treated  Oak  ties. 

Beech  trees  are  covered  with  smooth,  light-colored  bark. 
They  produce  small  prickly  burrs,  each  of  which  contains  two 
triangular,  sharp-edged  nuts,  which  are  sometimes  referred  to  as 
beech-mast,  and  which  yield  an  oil  that  is  occasionally  used  in 
place  of  olive  oil.  The  nuts  are  not  gathered  to  any  extent  in  the 
United  States. 


The  Coffee,  Coffeenut,  Coffeebean,  Coffeebean-tree,  or 
Mahogany  (Gymnocladus  dioicus). — These  trees  grow  best 
between  the  Alleghany  Mountains  and  the  Mississippi  River. 
They  are  valued  in  landscape  effects,  and,  in  many  places,  are 
cultivated.  The  strong,  durable,  reddish-brown  wood  works 
easily,  polishes  well,  and  can  be  used  in  cabinet  work. 

The  Hackberry,  Sugarberry,  One-berry,  Nettle-tree,  or 
False  Elm  (Celtis  occidentalis) . — This  tree  is  occasionally  found 
between  Canada  and  Florida  and  between  the  Atlantic  Coast  and 
the  Rocky  Mountains.  Isolated  specimens  are  sometimes  locally 
famed  as  " Unknown  Trees."  The  rather  hard,  strong  wood  is 
occasionally  used  in  fencing  andjn  cheap  furniture.2 

1  See  also  "Beech,  Birches  and  Maples,"  Maxwell  (United  States  Depart- 
ment of  Agriculture,  Bulletin  No.  12,  1913). 

2  See  also  "Hackberry,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  75,  1907). 

152 


BROADLEAF  TRUNKS  AND  WOODS  153 

Fagus  americana  Sweet 

Fagus  grandifolia 

Fagus  atropunicea  (Marsh}  Sudworth 

Fagus  ferruginea  Ait. 

NOMENCLATURE  (Sudworth).  White  Beech  (Me.,  Ohio,  Mich.). 

Beech  (local  and  common  name).          Ridge  Beech  (Ark.). 
Red  Beech  (Me.,  Vt.,  Ky.,  Ohio). 

LOCALITIES. 

Nova  Scotia  to  Florida,  westward  intermittently  to  Wisconsin  and  Texas. 

FEATURES  OF  TREE. 

Sixty  to  eighty  feet  in  height,  occasionally  higher;  two  to  four  feet  in  diame- 
ter; the  small,  rough  burrs  contain  two  thin-shelled  nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish,  variable  shades;  sapwood  white;  rather  close-grained; 
conspicuous  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  strong,  and  tough;  not  durable  when  exposed;  liable  to  check  during 
seasoning;  takes  a  fine  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Shoe-lasts,  plane-stocks,  ship-building,  handles,  and  fuel;  carpentry 
(abroad),  wagon-making,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

42. 
MODULUS  OF  ELASTICITY. 

1,720,000. 
MODULUS  OF  RUPTURE. 

16,300. 
REMARKS. 

There  is  but  one  species  of  Beech  in  North  America.  The  wood  is 
occasionally  divided  into  "Red  Beech"  and  "White  Beech,"  according 
to  its  color.  This  division  has  no  botanical  basis,  since  both  of  these 
woods  come  from  the  same  tree. 


154  ORGANIC  STRUCTURAL  MATERIALS 

Ironwood,  Blue  Beech.  Carpinus  caroliniana  Walt. 

NOMENCLATURE  (Sudworth). 

Ironwood,  Blue  Beech  (local  and  Hornbeam    (Me.,    N.    H.,    Mass., 

common  names).  R.  I.,  Conn.,  N.  Y.,  N.  J.,  Pa., 

Water  Beech  (R.  I.,  N.  Y.,  Pa.,  Del.,   N.   C.,   S.   C.,   Ala.,   Tex., 

Del.,  W.  Va.,  Ohio,  111.,  Ind.,  Ky.,  111.,  Kans.,  Minn.). 

Mich.,  Minn.,  Neb.,  Kans.). 

LOCALITIES. 

Quebec  to  Florida,  westward  intermittently  to  Nebraska  and  Texas. 

FEATURES  OF  TREE. 

Thirty  to  fifty  feet  in  height;  six  inches  to  occasionally  two  feet  in  di- 
ameter; a  small  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown;  thick  sapwood  nearly  white;  close-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Very  hard,  tough,  strong,  and  heavy;  very  stiff;  inclined  to  check  during 
seasoning;  not  durable  when  exposed. 

REPRESENTATIVE  USES  OF  WOOD. 
Levers,  tool-handles,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

45. 
MODULUS  OF  ELASTICITY. 

1,630,000. 
MODULUS  OF  RUPTURE. 

16,300. 
REMARKS. 


The  name  Ironwood  is  also  applied  to  the  Hornbeam  (Ostrya  virginiana), 
and  to  some  other  North  American  species  that  afford  unusually  hard, 
heavy  woods  suitable  for  handles  and  implements.  The  trunks  of  the 
species  known  as  Ironwoods  are  generally  small. 


BROADLEAF  TRUNKS  AND  WOODS  155 

Ironwood,  Hop  Hornbeam.  Ostrya  virginiana  Willd. 

NOMENCLATURE  (Sudworth). 

Ironwood,  Hop  Hornbeam  (local         Hornbeam  (R.  I.,  N.  Y.,  Fla.,  S.  C., 

and  common  names).  La.). 

Leverwood    (Vt.,    Mass.,    R.    I.,         Hardback  (Vt.). 
N.  Y.,  Pa.,  Kans.). 

LOCALITIES. 

Nova  Scotia  to  Florida,  westward  intermittently  to  North  Dakota,  South 
Dakota,  and  Texas. 

FEATURES  OF  TREE. 

Thirty  to  forty  feet  in  height;  one  foot  or  less  in  diameter;  the  bark  ex- 
hibits long,  vertical  rows  of  small  squares;  small  fruit  suggest  hops  in 
appearance;  the  leaves  resemble  those  of  the  Birch. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  reddish  brown,  sometimes  white;  sap  wood  lighter  or  white; 
close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Very  strong,  hard,  heavy,  and  tough;  durable  when  exposed. 

REPRESENTATIVE  USES  OF  WOOD. 

Posts,  levers,  tool-handles,  axe-helves,  mill-cogs,  and  wedges. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

51. 
MODULUS  OF  ELASTICITY. 

1,950,000. 
MODULUS  OF  RUPTURE. 

16,000. 
REMARKS. 
Trees  over  twelve  inches  in  diameter  are  often  hollow. 


SYCAMORE 

Platanus 

The  name  Sycamore  applies  to  a  Maple  (Acer  pseudo-platanus) 
in  Europe,  to  a  Fig  tree  (Ficus  sycomorus)  in  the  Orient,  and  to 
the  Buttonball  or  Plane  trees  (Platanus)  in  North  America.  Of 
the  Sycamore  or  Plane  trees,  the  Common  or  Oriental  Plane 
(Platanus  orientalis)  is  a  native  of  Europe;  the  Plane,  Buttonball, 
or  Sycamore  tree  (Platanus  occidentalis)  is  a  native  and  common 
tree  of  eastern  North  America;  and  the  California  Sycamore 
(Platanus  racemosa)  is  a  native  of  western  North  America.1 

American  sycamore  wood  is  tough,  strong,  and  difficult  to 
split.  The  cellular  structure  is  complicated,  and  a  typical  use  of 
the  wood  is  for  butcher's  blocks.  Because  of  its  beauty,  quar- 
tered sycamore  is  used  in  cabinet  work  and  indoor  finish. 

American  Plane,  Buttonball,  or  Sycamore  trees  are  distin- 
guished by  rough  heads  or  balls,  which  remain  hanging  on  long 
stems  throughout  the  winter.  The  bark  is  also  characteristic. 
Large  flakes  of  the  outer  bark  drop  away  and  expose  inner  sur- 
faces, so  smooth  and  white  that  they  appear  to  be  painted.  Six 
or  seven  species  are  included  in  this  genus.  Three  of  the  species 
occur  in  North  America. 


1  The  sycamore  possesses  an  emblematic  interest  because  of  its  biblical 
association  with  Zaccheus.  Many  European  sycamores  were  planted  by 
religious  persons  during  the  Middle  Ages  because  of  the  belief  that  they 
were  the  trees  referred  to  in  the  Bible. 

156 


BROADLEAF  TRUNKS  AND  WOODS  157 

Sycamore,  Buttonwood,  Buttonball-tree.        Platanus  occidentalis  Linn. 

NOMENCLATURE  (Sudworth). 

Sycamore,  Buttonwood,  Button-  Plane  Tree  (R.  I.,  Del.,  S.  C.,  Kans., 

ball-tree    (local    and    common  Neb.,  la.). 

names).  Water  Beech  (Del.). 

Buttonball    (R.    I.,    N.   Y.,    Pa.,  Platane,  cotonier,  Bois  puant  (La.). 

Fla.). 

LOCALITIES. 

Maine  and  Ontario  to  Florida,  westward  intermittently  to  Nebraska  and 
Texas;  best  in  the  bottom  lands  of  the  Ohio  and  Mississippi  River 
basins. 

FEATURES  OF  TREE. 

Ninety  to  over  one  hundred  feet  in  height;  six  to  sometimes  twelve  feet 
in  diameter;  the  inner  bark  is  exposed  in  white  patches;  the  rough  balls 
or  heads  are  about  one  inch  in  diameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  reddish-brown;  sap  wood  lighter;  close-grained;  compact 
structure;  satiny;  conspicuous  medullary  rays;  the  wood  is  attractive 
when  quartered. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  difficult  to  work;  not  strong;  stands  well  when  not 
exposed. 

REPRESENTATIVE  USES  OF  WOOD. 

Tobacco-boxes,  ox-yokes,  butcher-blocks,  and  cabinet-work. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

35. 
MODULUS  OF  ELASTICITY. 

1,220,000. 
MODULUS  OF  RUPTURE. 

9,000. 
REMARKS. 

Some  specimens  are  among  the  largest  of  American  deciduous  trees,  but 
the  bottoms  of  such  exceptionally  large  trees  are  usually  hollow.  The 
bark  is  thin  and  soft  when  the  tree  is  young  but  becomes  thicker  and 
harder  as  the  tree  grows  older,  until  a  point  is  reached  when  it  can  no 
longer  stretch  to  accommodate  the  growth  of  the  tree.  Large  areas  of 
the  bark  are  then  thrown  off  by  the  tree  and  the  inner  surfaces  which  are 
exposed  appear  so  smooth  and  white  as  to  suggest  the  possibility  that 
they  have  been  painted. 


158  ORGANIC  STRUCTURAL  MATERIALS 

California  Sycamore.  Platanus  racemosa  Nutt. 

NOMENCLATURE. 

Sycamore,  Button  wood,  Buttonball  Tree,  Buttonball  (California). 

LOCALITIES. 

California  and  Lower  California. 

FEATURES  OP  TREE. 

Seventy-five  to  one  hundred  feet  in  height,  occasionally  higher;  three  to 
four  feet  in  diameter;  differs  from  the  Sycamore  (Platanus  occidentalis) 
in  that  the  balls  or  heads  are  in  clusters  and  not  solitary;  the  bark  exfo- 
liates in  irregular  patches. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  reddish  brown;  sapwood  lighter;  close-grained;  compact 
structure;  the  medullary  rays  are  numerous  and  conspicuous;  the  wood 
is  quite  attractive  when  quartered. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Brittle,  very  difficult  to  split  and  season;  the  qualities  are  similar  to  those 
of  the  Sycamore  (Platanus  occidentalis) . 

REPRESENTATIVE  USES  OF  WOOD. 

Decoration  and  furniture;  used  as  the  wood  of  the  Sycamore  (Plalanus 
occidentalis)  is  used. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

30. 
MODULUS  OF  ELASTICITY. 

800,000. 
MODULUS  OF  RUPTURE. 

7,900 
REMARKS. 


BIRCH 

Betula 

Birch  trees  grow  in  many  places  in  North  America,  Europe, 
and  Asia.  The  ranges  of  some  species  extend  far  into  the  North. 
Birch  trees  are  noted  for  their  bark,  quite  as  much  as  for  their 
wood.1 

The  Paper  Birch  (Betula  papyrifera)  is  the  species  that  is 
most  noted  for  its  bark,  which  is  smooth,  pliable,  inflammable, 
water-tight,  of  a  cream  or  ivory-white  color,  and  marked  with 
long,  horizontal,  raised  dashes  or  lenticels.  The  bark  contains 
resinous  oils  and  is  so  durable  that  it  often  remains  intact  on 
fallen  trees,  long  after  the  wood  inside  has  rotted  and  disappeared. 
The  layers,  of  which  it  is  composed,  separate  easily  from  one 
another  and  can  be  obtained  in  large-sized  pieces.  The  North 
American  Indians  employed  it  for  canoes,  tents,  troughs,  and 
buckets.  It  has  also  been  used  to  write  upon  and  to  cover 
houses. 

The  Yellow  Birch  (Betula  lutea)  and  the  Sweet  Birch  (Betula 
lento)  are  prized  for  their  hard,  heavy,  strong,  fine-grained,  and 
attractive  woods,  which,  however,  are  not  durable  in  exposed 
positions.  These  woods  are  used  in  spools,  woodenware,  in- 
terior finish,  and  furniture.  They  are  often  stained  so  as  to 
imitate  cherry  and  mahogany.  One  of  the  best  of  the  "imita- 
tion mahoganies"  is  obtained  by  staining  Birch.  The  European 
Birch  (Betula  alba)  yields  the  cheapest  native  hardwood  obtain- 
able in  many  parts  of  Europe.  This  wood,  which  is  moderately 
hard  and  strong,  but  not  durable,  is  used  for  furniture,  plates, 
spoons,  sabots,  and  similar  objects.  The  Russians  glue  rotary- 
cut  veneers  of  birch  across  one  another  and  form  thin,  rigid 
planks  that  are  used  for  tea-chests  and  chair-bottoms.  Occa- 
sional burrs  yield  figured  woods  that  are  turned  into  cups,  bowls 
and  mallets. 

1  See  also  "  Beech,  Birches  and  Maples,"  Maxwell  (United  States  De- 
partment of  Agriculture  Bulletin  No.  12,  1913);  "The  Birches,"  Detwiler 
(American  Forestry,  April,  1916). 

159 


160  ORGANIC  STRUCTURAL  MATERIALS 

White  Birch.  Betula  populifolia  Marsh 

NOMENCLATURE  (Sudworth).  Oldfield  Birch,  Poverty  Birch  (Me.). 

White  Birch  (local  and  common  Poplar-leaved  Birch,   Small  White 

name).  Birch  (Vt.). 
Gray  Birch  (Me.,  R.  I.,  Mass.). 

LOCALITIES. 

Atlantic  Coast,  Canada  to  Delaware  and  Kentucky. 

FEATURES  OF  TREE. 

Twenty  to  forty  feet  in  height;  rarely  one  foot  in  diameter;  durable,  lam- 
inated, smooth  white  bark  on  the  large  branches  and  on  the  trunk,  save 
near  the  ground;  the  bark  is  not  very  easily  detached  from  the  tree. 

COLOR,  GRAIN,  OR  APPEARANCE  OF  WOOD. 

Heartwood  light  brown;  sapwood  lighter;  close-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Soft  and  light;  not  strong  or  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

Clothes-pins,  shoe-pegs,  toothpicks,  and  paper-pulp. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

35. 
MODULUS  OF  ELASTICITY. 

1,036,000. 
MODULUS  OF  RUPTURE. 

11,000. 
REMARKS. 

The  white  bark  is  distinct  from  that  of  the  Paper  Birch  (Betula  papyrifera) 
in  that  it  does  not  cover  the  whole  trunk.  The  layers  split  less  easily 
from  one  another. 


BROADLEAF  TRUNKS  AND  WOODS  161 

Paper  Birch,  White  Birch.  Betula  papyrifera  Marsh 

NOMENCLATURE  (Sud worth). 

Paper  Birch,  White  Birch  (local  Boleau  (Quebec). 

and  common  names).  Canoe  Birch  (Me.,  Vt.,  N.  H.,  R.  I., 

Silver  Birch  (Minn.).  Mass.,  N.  Y.,  Pa.,  Wis.,    Mich., 

Large  White  Birch  (Vt.).  Minn.). 

LOCALITIES. 

Northern  United  States,  northward  into  Canada  and  to  the  valley  of  the 
Yukon  in  Alaska. 

FEATURES  OF  TREE. 

Fifty  to  seventy  feet  in  height;  one  and  one-half  to  two  and  one-half 
feet  in  diameter;  smooth  white  exterior  bark  on  large  limbs  and  on 
trunks  at  a  distance  from  the  ground;  brown  or  orange-colored  inner 
surfaces  of  bark;  the  bark  splits  freely  into  thin,  paper-like  layers. 

COLOR,  GRAIN,  OR  APPEARANCE  OF  WOOD. 

Heartwood  brown,  tinged  with  red;  sapwood  nearly  white;  very  close- 
grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong,  hard,  and  tough;  is  not  durable  when  exposed  to  the  weather; 
the  bark  takes  fire  easily,  even  when  it  is  wet. 

REPRESENTATIVE  USES  OF  WOOD. 

Spools,  shoe-lasts,  pegs,  pill-boxes,  paper-pulp,  and  fuel;  the  bark  was  used 
in  canoes. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

37. 
MODULUS  OF  ELASTICITY. 

1,850,000. 
MODULUS  OF  RUPTURE. 

15,000. 
REMARKS. 

These  trees  grow  at  higher  latitudes  than  most  other  American  deciduous 
trees.  They  form  forests.1 


1  See  also  "Paper  Birch,  Betula  papyrifera  Marsh"  (United  States  Forest 
Service,  Silvical  Leaflet  No.  38,  1908). 
11 


162  ORGANIC  STRUCTURAL  MATERIALS 

Red  Birch.  Betula  nigra  Linn. 

NOMENCLATURE  (Sudworth). 

Red  Birch  (local  and  common  River  Birch  (Mass.  R.  I.,  N.  J., 
name).  Del.,  Pa.,  W.  Va.,  Ala.,  Miss., 

Black  Birch  (Fla.,  Tenn.,  Tex.).  Tex.,  Mo.,  111.,  Wis.,  Ohio). 

Birch  (N.  C.,  S.  C.,  Miss.,  La.).  Water  Birch  (W.  Va.,  Kans.). 

Blue  Birch  (Ark.). 
LOCALITIES. 

Massachusetts  to  Florida,  westward  intermittently  to  Nebraska  and 
Texas;  best  development  in  South  Atlantic  and  lower  Mississippi  valley 
regions. 

FEATURES  OF  TREE. 

Thirty  to  eighty  feet  in  height;  one  to  three  feet  in  diameter,  sometimes 
larger;  dark  red-brown  scaly  bark  on  trunk;  red  to  silver-white  bark  on 
branches;  the  bark  separates  into  thin,  paper-like  scales,  which  curl 
outward. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  light  brown;  sapwood  yellowish  white;  close-grained,  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  rather  hard,  and  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Furniture,  wooden  ware,  shoe-lasts,  and  ox-yokes;  inferior  cask -hoops  are 
made  from  the  branches;  also  used  as  a  base  upon  which  enamelled 
paints  are  applied. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

35. 
MODULUS  OF  ELASTICITY. 

1,580,000. 
MODULUS  OF  RUPTURE. 

13,100. 
REMARKS. 

Dark-brown  bark,  whence  the  name  Red  Birch.  Prefers  moist  bottoms, 
whence  the  name  River  Birch. 


BROADLEAF  TRUNKS  AND  WOODS  163 

Yellow  Birch.  Betula  lutea  Michx.  f. 

NOMENCLATURE  (Sudworth). 

Yellow  Birch  (local  and  common         Swamp  Birch  (Minn.). 

name).  Silver  Birch  (N.  H.). 

Gray  Birch  (Vt.,  R.  I.,  Pa.,  Mich.,         Merisier,  Merisier  Rouge  (Quebec). 

Minn.). 
American  Mahogany. 

LOCALITIES. 

Newfoundland  to  North  Carolina,  westward  intermittently  to  Manitoba 
and  Texas;  best  developed  north  of  the  Great  Lakes. 

FEATURES  OP  TREE. 

Sixty  to  eighty  or  more  feet  in  height;  two  to  four  feet  in  diameter;  a 
medium-sized  tree;  the  bark  on  the  trunk  is  silver-gray  to  silver-yellow, 
while  the  bark  on  the  branches  varies  between  green  and  lustrous  or 
dull-brown;  the  bark  exfoliates,  causing  a  rough,  ragged  appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  reddish  brown;  sapwood  nearly  white;  close-grained; 
compact  structure;  satin-like  appearance. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  strong,  hard,  and  tough;  is  susceptible  to  a  high  polish;  the  quali- 
ties suggest  those  of  Maple;  is  not  durable  when  exposed  to  the  weather. 

REPRESENTATIVE  USES  OF  WOOD. 

Furniture,  buttons,  tassel-moulds,  pill-boxes,  spools,  wheel-hubs,  and 
chair  seats;  occasional  burls  are  valued  for  making  mallets;  the  wood  is 
also  used  as  a  base  upon  which  enamelled  paints  are  applied. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

40. 
MODULUS  OF  ELASTICITY. 

2,290,000. 
MODULUS  OF  RUPTURE. 

17,700. 
REMARKS. 

The  thin  outer  bark  is  sometimes  ruptured  in  such  a  way  as  to  show  the 
almost  metallic  yellow  of  the  inner  bark.  The  name  is  due  to  the 
yellow  appearance  of  the  inner  bark,  which  is  also  characterized  by  the 
fact  that  it  possesses  a  pungent,  pleasant  flavor. 


164  ORGANIC  STRUCTURAL  MATERIALS 

Sweet  Birch,  Cherry  Birch.  Betula  lenla  Linn. 

NOMENCLATURE  (Sudworth).  Black   Birch    (N.   H.,   Vt.,    Mass., 

Sweet  Birch,  Cherry  Birch.  R.  I.,  Conn.,  N.  Y.,  N.  J.,  Pa., 

(many  localities).  W.   Va.,    Ga.,    111.,    Ind.,    Mich., 

Mahogany  Birch  (N.  C.,  S.  C.).  Ohio). 

River  Birch  (Minn.).  Mountain  Mahogany  (S.  C.). 

LOCALITIES. 

Newfoundland,  intermittently  to  Illinois,  southward  intermittently  along 
the  Alleghanies  to  Kentucky,  Tennessee,  and  Florida. 

FEATURES  OF  TREE. 

Fifty  to  eighty  feet  in  height;  three  to  four  feet  in  diameter;  the  dark  red- 
dish-brown bark  resembles  that  of  the  Cherry;  it  does  not  separate  into 
layers  as  in  the  case  of  the  Paper  Birch  (Betula  papyrifera) ;  the  leaves, 
bark,  and  twigs  are  sweet,  spicy,  and  aromatic. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark  brown,  tinged  with  red;  sapwood  light  brown  or  yellow; 
close-grained ;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  very  strong,  and  hard ;  the  wood  is  often  stained  so  as  to  resemble 
cherry  and  mahogany;  it  is  also  used  as  a  base  upon  which  enamelled 
paints  are  applied. 

REPRESENTATIVE  USES  OF  WOOD. 

Woodenware,  furniture,  ship-building  (Canada),  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

47. 
MODULUS  OF  ELASTICITY. 

2,010,000. 
MODULUS  OF  RUPTURE. 

17,000. 
REMARKS. 

A  common  tree  in  some  of  the  Northern  States.  The  name  Cherry  Birch 
is  due  to  the  bark,  the  appearance  of  which  suggests  that  of  the  Cherry 
tree.  The  name  Sweet  Birch  is  due  to  the  sweet,  spicy  essences  in  the 
bark. 


LOCUST,  MESQUITE 

Robinia,  Gleditsia,  Prosopis 

The  name  Locust  applies  to  species  of  three  distinct  genera  of 
•the  family  Leguminosse.  The  Black  Locust  (Robinia  pseud- 
acacia),  the  Honey  Locust  (Gleditsia  triacanthos) ,  and  the  Mesquite 
or  Honey  Locust  (Prosopis  juli flora)  grow  in  the  United  States.1 

The  wood  of  the  Black  Locust  is  noted  for  toughness,  dura- 
bility, and  great  torsional  strength.  Black  Locust  trenails  and 
wheel-spokes  have  few,  if  any,  superiors.  Black  Locust  trees 
may  be  known  by  their  clusters  of  large  peablossom-shaped 
flowers  and  by  their  bean-shaped  pods,  which  are  from  three  to 
six  inches  in  length.  The  large  thorns  on  the  trunks  are  also 
characteristic.  There  are  several  species  and  varieties  of  the 
genus  Robinia  in  the  United  States. 

The  wood  of  the  Honey  Locust  resembles  that  of  the  Black 
Locust,  but  is  seldom  used,  save  in  rough  constructions,  as  fence 
rails.  The  Honey  Locust  bears  blossoms  that  are  smaller  than 
those  of  the  Black  Locust,  but  the  pods  of  the  Honey  Locust  are 
from  ten  to  eighteen  inches  long.  There  are  several  species  and 
varieties. 

The  wood  of  the  Mesquite  is  hard,  heavy,  and  practically 
indestructible  when  exposed.  Mesquite  beams  exist  in  some 
native  houses  in  the  Southwest,  and  Mesquite  railway  ties  and 
fence  posts  are  also  occasionally  seen.  Mesquite  trees  are  found 
where  those  of  other  species  cannot  grow.  They  can  survive 
when  almost  entirely  covered  with  sand.  To  the  localities  in 
which  they  grow,  they  are  much  as  Bamboos  are  to  China  and 
Japan.  The  woods  themselves  are  valued;  the  rich,  pulpy  pods 
are  used  as  food ;  a  mucilage  is  made  from  the  gum ;  and  a  dye  is 
made  from  the  sap.  One  other  species,  the  Screwpod  Mesquite 
(Prosopis  odorata)  is  found  in  the  United  States. 

1  See  also  "An  Economic  Study  of  Acacias/'  Shinn  ("United  States  Depart- 
ment of  Agriculture,  Bulletin  No.  9,  1913).  "The  Locusts/'  Detwiler 
(American  Forestry,  February,  1917). 


165 


166  ORGANIC  STRUCTURAL  MATERIALS 

Locust,  Black  Locust,  Yellow  Locust.         Robinia  pseudacacia  Linn. 

NOMENCLATURE  (Sudworth).  Red  Locust,  Green  Locust  (Term.). 

Locust,     Black    Locust,    Yellow         Honey  Locust  (Minn.). 

Locust     (local     and     common         White  Locust  (R.  I.,  N.  Y.,  Tenn.). 

names).  Acacia  (La.). 

False  Acacia  (S.  C.,  Ala.,  Tex., 

Minn. 
Pea-flower  Locust,   Post  Locust 

(Md.). 

LOCALITIES. 

Mountains,  Pennsylvania  to  Georgia,  westward  to  Iowa  and  Kansas; 
widely  naturalized  in  the  northeastern  part  of  the  United  States. 

FEATURES  OF  TREE. 

Fifty  to  seventy  feet  in  height;  two  to  three  feet  or  over  in  diameter;  the 
seven  to  seventeen  leaflets  curl  up  or  close  at  night ;  there  are  long  spines 
on  young  branches. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish;  the  thin  sap  wood  is  of  a  light  greenish-yellow  color; 
close-grained  and  compact;  the  annual  layers  are  clearly  marked. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  durable  when  exposed  to  the  weather. 

REPRESENTATIVE  USES  OF  WOOD. 

Long  wooden  bolts  or  pins  called  trenails ;  posts,  ties,  construction,  turnery, 
ship-ribs,  ornamentation,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

45. 
MODULUS  OF  ELASTICITY. 

1,830,000. 
MODULUS  OF  RUPTURE. 

18,100. 
REMARKS. 

Extensively  planted,  particularly  in  the  West.  Subject  to  attacks  by 
insect-borers.  One  of  the  most  valuable  timber  trees  in  the  United 
States.  Heartwood  forms  very  early  in  the  life  of  this  tree. 


BROADLEAF  TRUNKS  AND  WOODS  167 

Honey  Locust.  Gleditsia  triacanthos  Linn. 

NOMENCLATURE  (Sud worth).  Honey  or  Honeyshucks  (R.  I.,  N.  J., 

Honey  Locust  (local  and  common  Va.,  Fla.,  La.). 

name).  Honeyshucks  Locust  (Ky.). 

Thorn  or  Thorny  Locust  Tree  or  Sweet    Locust   (S.   C.,    La.,   Kan., 

Acacia    (N.    Y.,    N.    J.,    Ind.,  Neb.). 

Tenn.,  La.).  Piquant  Amourette  (La.). 

Three-thorned     Acacia        (Mass.,  Confederate  Pintree  (Fla.). 

R.  I.,  La.,  Tex.,  Neb.,  Mich.).  Locust  (Neb.). 
Black  Locust  (Miss.,  Tex.,  Ark., 

Kan.,  Neb.). 

LOCALITIES. 

Ontario  and  Pennsylvania  to  Florida,  westward  intermittently  to  Ne- 
braska and  Texas;  best  in  lower  Ohio  River  basin. 

FEATURES  OP  TREE. 

Seventy  to  ninety  feet  or  more  in  height;  two  to  four  feet  in  diameter; 
long  spines  are  plentiful  on  some  individuals,  but  are  absent  on  others; 
the  brown  fruit  pods,  which  are  from  ten  to  eighteen  inches  long,  contain 
sweetish,  succulent  pulp. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood   bright  brown   or   red;   sap  wood   yellowish;   annual   layers 
strongly  marked;  coarse-grained;  the  medullary  rays  are  conspicuous. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  very  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Fence-posts,  rails,  wagon-hubs,  rough  construction  work,  etc.1 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

42. 
MODULUS  OF  ELASTICITY. 

1,540,000. 
MODULUS  OF  RUPTURE. 

13,100. 
REMARKS. 

These  trees  are  widely  cultivated  for  landscape  effects.  They  are  also 
used  in  hedges. 


1  See  also  "Honey  Locust,"  Pinchot  (United  States  Forest  Service,  Cir- 
cular No.  74,  1907). 


168  ORGANIC  STRUCTURAL  MATERIALS 

Mesquite.  Prosopis  juliflora  de  C. 

NOMENCLATURE  (Sudworth)  Honey  Pod  or  Honey  Locust  (Tex., 

Mesquite    (Tex.,    N.    M.,    Ariz.,  N.  M.). 

Cal.).  Ironwood  (Tex.). 

Algaroba    (Tex.,    N.    M.,    Ariz., 

Cal.). 

LOCALITIES. 

Texas,  west  to  the  San  Bernardino  Mountains  in  California.  Also 
Colorado,  Utah,  Nevada,  and  northern  Mexico.  Mesquite  trees  are 
cultivated  in  Hawaii. 

FEATURES  OF  TREE. 

Forty  to  fifty  feet  in  heigth;  one  to  two  feet  in  diameter;  sometimes  a  low 
shrub;  the  roots  are  often  very  large;  the  pods  contain  a  sweet  pulp; 
there  are  gums  which  resemble  gum  arabic. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  rich  dark  brown,  often  red;  sapwood  clear  yellow;  close- 
grained;  compact  structure;  distinct  medullary  rays. 

STRUCTURAL  QUALITIES  OP  WOOD. 

Weak,  difficult  to  work,  heavy,  hard,  and  very  durable  receives  a  high 
polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Posts,  fencing,  ties,  house-beams,  fuel,  and  charcoal. 


WEIGHT  OP  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

47. 
MODULUS  OP  ELASTICITY. 

820,000. 
MODULUS  OP  RUPTURE. 

6,800. 
REMARKS. 

The  Mesquite  tree  can  survive  when  almost  entirely  covered  with  sand. 
The  roots  develop  greatly  in  their  search  for  water,  and  are  often  dug  up 
and  used  for  fuel  in  localities  where  there  is  nothing  better.  The 
tree  is  important  locally. 


CHAPTER  VII 

BANDED  TRUNKS  AND  WOODS  (CONTINUED) 
BROADLEAF  SERIES,  PART  Two 

Dicotyledons 

WHITEWOOD    OR   TULIP-TREE   WOOD.     POPLAR   OR  COTTON- 
WOOD.     CUCUMBER-TREE  WOOD.     BASSWOOD. 

Liriodendron.    Populus.     Magnolia.     Tilia. 

These  unrelated  trees  are  grouped  together  because  they  yield 
similar,  soft,  clean,  fine-grained  woods  that  are  all  valued  for 
indoor  work.  The  woods  all  last  well  when  protected  from  the 
weather,  but  no  one  of  them  is  durable  when  exposed. 

The  Whitewood  or  Tulip-tree  (Liriodendron  tulipifera)  is  a 
native  of  North  America.  The  wood,  which  is  the  best  of  its 
kind,  is  soft,  rigid,  fine-grained,  clean,  free  from  knots,  straight- 
grained,  capable  of  being  nailed  without  splitting,  and  obtainable 
in  large-sized  pieces.  It  is  used  for  boxes,  shelves,  the  bottoms 
of  drawers,  and  house-trim.  In  spite  of  its  name,  it  is  of  a 
greenish-yellow  color.  The  trees  are  often  very  large.  Mat- 
thews1 mentions  a  specimen  that  was  thirty-nine  feet  in  circum- 
ference. Whitewood  trees  may  be  known  by  their  large  tulip- 
shaped  flowers. 

Poplar  Trees  Grow  on  Both  Hemispheres. — The  tough,  light 
woods  will  indent  without  breaking,  and  were  formerly  used  for 
shields.  The  woods  are  now  used  much  as  whitewood  is  used, 
for  trunks,  boxes,  woodenware,  and  indoor  finish,  but  they  are 
not  as  good  as  whitewood.  The  trees  are  sometimes  called 
Cottonwoods  because  their  seeds  are  covered  with  a  cotton-like 
down.  The  foliage  of  some  species,  as  the  Aspen  (Populus 
tremuloides) ,  is  agitated  by  the  slightest  wind.  This  is  due  to  the 
shape  of  the  long  leaf-stems2. 

The  Balsam  Poplar  or  Balm  of  Gilead  (Populus  balsamifera) , 
which  thrives  far  into  the  North,  must  not  be  confused  with  the 
true  Balsam  or  Balm  of  Gilead  (Abies  balsamea).  Sudworth 
credits  twelve  species  of  the  genus  Populus  to  the  United  States. 

The  Cucumber-tree  (Magnolia  acuminata)  is  a  member  of  the 
Magnolia  family,  and  yields  a  wood  that  is  seldom  distinguished 
commercially  from  Whitewood. 

169 


170  ORGANIC  STRUCTURAL  MATERIALS 

Basswood  Trees  are  Known  by  Many  Names. — Limes,  Lime- 
trees,  Lind,  Linden,  Tiel,  Tieltrees,  Beetrees,  Bass,  and  Basswood 
trees  are  the  same.  The  woods  are  prized  for  their  working 
qualities  which  resemble,  but  are  inferior  to  those  of  white  wood; 
and  the  trees  are  prized  for  their  dense  shade  and  fine  appearance. 
The  Basswood  (Tilia  americana)  is  the  principal  species  in  the 
United  States.  Basswood  trees  bear  small,  fragrant,  cream- 
colored  flowers  that  are  often  surrounded  by  bees. 


"Familiar  Trees,"  F.  Schuyler  Matthews  (p.  39,  Appleton,  1901). 
2  See  also  "The  Aspens,"  Weigle  and  Frothingham  (United  States  Forest 
Service,  Bulletin  No.  93,  1911);  "Cottonwood  in  the  Mississippi  Valley," 
Williamson   (United  States  Department  of  Agriculture,  Bulletin  No.  24, 
1913.) 


BROADLEAF  TRUNKS  AND  WOODS  171 

Tulip  Tree,  Whitewood,  Yellow  Poplar.       Liriodendron  tulipifera  Linn. 

NOMENCLATURE  (Sudworth). 

Tulip  Tree,  Whitewood,  Yellow  Hickory  Poplar  (Va.,  W.  Va., 

Poplar  (local  and  common  names).  N.  C.). 

Poplar  (R.  I.,  Del.,  N.  C.,  S.  C.,  Fla.,  Blue  Poplar  (Del.,  W.  Va.). 

Ohio).  Popple  (R.  I.). 

Tulip  Poplar  (Del.,  Pa.,  S.  C.,  111.).  Cucumber  Tree  (N.  Y.). 

Canoewood  (Tenn.). 
LOCALITIES. 

New  England  to  Florida,  westward  intermittently  to  Michigan  and 
Arkansas. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  and  fifty  feet  in  height;  six  to  twelve  feet  in  di- 
ameter; tulip-shaped  flowers  appear  in  the  spring;  the  greenish  cone-like 
fruit  dries  and  remains  after  the  leaves  have  fallen. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  yellow  or  greenish  brown;  the  thin  sapwood  is  nearly 
white;  close  and  straight-grained;  compact  structure;  free  from  knots. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  moderately  strong,  but  brittle;  easily  worked;  not  dur- 
able in  contact  with  the  ground;  hard  to  split;  shrinks  little;  resembles 
White  Pine  (Pinus  strobus);  stands  well  in  protected  places. 

REPRESENTATIVE  USES  OF  WOOD. 

Lumber,  interior  finish,  woodenware,  shelves,  and  bottoms  of  drawers; 
used  as  a  base  upon  which  enamelled  paints  are  applied. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

26. 
MODULUS  OF  ELASTICITY. 

1,300,000. 
MODULUS  OF  RUPTURE. 

9,300. 
REMARKS. 

Very  large  trees  were  formerly  common.  Whitewood  is  sometimes 
divided  by  lumbermen  into  "White  Poplar"  and  "Yellow  Poplar." 
One  of  the  largest  and  most  useful  of  American  deciduous  trees. 


172  ORGANIC  STRUCTURAL  MATERIALS 

Poplar,  Largetooth  Aspen.  Populus  grandidentata  Michx. 

NOMENCLATURE  (Sudworth). 

Poplar,  Largetooth  Aspen  (local         White  Poplar  (Mass.). 

and  common  names).  Popple  (Me.). 

Largetooth  Poplar  (N.  C.).  Large  American  Aspen  (Ala.). 

Large  Poplar  (Tenn.). 

LOCALITIES. 

Nova  Scotia  and.  Delaware,  westward  intermit tentty  to  Minnesota. 
Alleghany.  Mountains,  to  Kentucky,  and  Tennessee. 

FEATURES  OP  TREE. 

Sixty  to  eighty  feet  in  height;  two  feet  or  more  in  diameter;  there  are 
irregular  points  or  teeth  on  the  margins  of  the  leaves;  the  flowers 
appear  before  the  leaves  in  the  spring;  the  gray  bark  is  smooth. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish;  sapwood  nearly  white;  close-grained;  compact 
structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Soft,  light,  and  weak. 

REPRESENTATIVE  USES  OF  WOOD. 

Paper-pulp  and  occasionally  woodenware. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,360,000. 
MODULUS  OF  RUPTURE. 

10,200. 
REMARKS. 

The  Quaking  Aspen  (Populus  tremuloides)  has  long  leafstalks,  flattened 
vertically  to  the  leaf-surfaces,  which  cause  the  leaves  to  tremble  in 
slight  winds.  This  characteristic  is  more  or  less  pronounced  with  other 
species  of  the  genus  Populus. 


Ailanthus  (Ailanthus  glandulosa).  This  sturdy,  beautiful,  very  quick- 
growing,  but  short-lived  tree  was  once  popular  in  the  United  States,  par- 
ticularly in  city  landscapes,  but  it  was  discarded  because  of  the  disagree- 
able, far-reaching  odor  of  its  flowers.  The  tree  has  many  merits.  In 
Europe,  the  wood  is  used  for  woodenware  and  charcoal;  in  China,  certain 
silkworms  feed  upon  the  leaves  of  the  trees.  The  Chinese  call  the  Ailanthus 
the  "Tree  of  Heaven."  American  specimens  have  grown  in  excess  of  ten 
feet  in  length  during  the  first  year. 


BROADLEAF  TRUNKS  AND  WOODS  173 

„  ,  IPopulus  deltoides  Marsh 

Cottonwood.  1  r>       7  -7  •*       A  M 

(Populus  monihfera  Ait. 

NOMENCLATURE  (Sudworth). 

Cottonwood  (local  and  common         Big  Cottonwood  (Miss.,  Neb.). 

name).  Whitewood  (la.). 

Carolina  Poplar  (Pa.,  Miss.,  La.,         Cotton  Tree  (N.  Y.). 

N.  M.,  Ind.,  Ohio).  Necklace  Poplar  (Tex.,  Colo.). 

Yellow    Cottonwood    (Ark.,  la.,         Broadleaved  Cottonwood  (Colo.). 

Neb.). 

LOCALITIES. 

Canada  to  Florida,  westward  intermittently  to  Rocky  Mountains. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height;  four  to  five  feet  in  diameter; 
occasionally  much  larger;  long  catkins  distribute  cotton-like  fibers. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Thin  heartwood  dark  brown;  sapwood  nearly  white;  close-grained;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  soft,  weak,  liable  to  warp,  and  difficult  to  season. 

REPRESENTATIVE  USES  OF  WOOD. 

Greatly  valued  in  the  manufacture  of  paper-pulp;  also  used  for  packing- 
boxes,  fence-boards,  and  fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

24. 
MODULUS  OF  ELASTICITY. 

1,400,000. 
MODULUS  OF  RUPTURE. 

10,900. 
REMARKS. — 


See  also  "Cottonwood"  (United  States  Forest  Service,  Circular  No.  77). 


174  ORGANIC  STRUCTURAL  MATERIALS 

Black  Cottonwood.  Populus  trichocarpa  Ton.  and  Gr. 

NOMENCLATURE  (Sud worth).  Cottonwood  (Oreg.,  Cal.). 

Black  Cottonwood  (Oreg.,  Cal.).          Balm  Cottonwood  (Cal.). 
Balsam  Cottonwood,  Balm  (Oreg.). 

LOCALITIES. 

Pacific  Coast  region,  Alaska  to  California. 

FEATURES  OF  TREE. 

A  large  tree,  sometimes  one  hundred  and  fifty  feet  in  height  and  four  to  six 
feet  in  diameter;  the  broadly  ovate  leaves  have  blunt,  marginal  teeth. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  dull  brown;  sapwood  nearly  white;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  soft,  and  weak. 

REPRESENTATIVE  USES  OF  WOOD. 
Staves,  and  sometimes  woodenware. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

23. 
MODULUS  OF  ELASTICITY. 

1,580,000. 
MODULUS  OF  RUPTURE. 

8,400. 
REMARKS. 

The  largest  deciduous  tree  of  the  Puget  Sound  district. 


The  Cottonwood,  Tacmahac,  Balsam,  Balsampoplar,  or  Balm  of  Gilead 
(Populus  balsamifera)  which  grows  from  Hudson  Bay  and  Alaska,  southward 
to  Oregon  and  New  England  is  a  distinctly  northern  species.  The  large 
upright  trunk  yields  a  light,  soft,  light-colored  wood  which  has  been  used  in 
making  paper.  The  exudations  are  sometimes  used  in  medicine. 


BROADLEAF  TRUNKS  AND  WOODS  175 

Cucumber-tree.  Magnolia  acuminata  Linn. 

NOMENCLATURE  (Sudworth).  Mountain  Magnolia  (Miss.,  Ky.). 

Cucumber-tree  (R.  I.,  Mass.,  N.  Y.,  Black  Lin,  Cucumber  (W.  Va.). 

Pa.,  N.  C.,  S.  C.,  Ala.,  Miss.,  La.,  Magnolia  (Ark.). 
Ark.,  Ky.,  W.  Va.,  Ohio,  Ind.,  111.). 

LOCALITIES. 

New  York  to  Illinois,  southward  intermittently  through  Kentucky  and 
Tennessee  to  the  Gulf. 

FEATURES  OF  TREE. 

Fifty  to  occasionally  one  hundred  feet  in  height;  two  to  four  feet  in  diame- 
ter; a  large,  handsome,  symmetrical  tree,  with  fruit  suggesting  cucum- 
bers; large  greenish-yellow  or  cream-colored  flowers. 

COLOR,  APPEARANCE  OR  GRAIN  OF  WOOD. 

Heartwood  brownish  yellow ;  sap  wood  nearly  white;  close-grained;  com- 
pact structure;  thin  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  soft,  not  strong,  but  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

Cabinet-making,  cheap  furniture,  flooring,  pump-logs,  troughs,  crates, 
and  packing-boxes. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

29. 
MODULUS  OF  ELASTICITY. 

1,310,000. 
MODULUS  OF  RUPTURE. 

9,500. 
REMARKS. 

The  wood  resembles  and  is  often  sold  for  that  obtained  from  the  Tulip  Tree 
(Liriodendron  lulipifera). 


176  ORGANIC  STRUCTURAL  MATERIALS 

Basswood,  Linn,  Linden.  Tilia  americana  Linn. 

NOMENCLATURE  (Sudworth).  Whitewood    (Vt.,    W.    Va.,    Ark., 

Basswood,  Linn,  Linden,  Ameri-  Minn.). 

can  Linden  (local  and  common  Yellow  Basswood,  Lein  (Ind.). 

names).  Beetree  (Vt.,  W.  Va.,  Wis.). 

Limetree  (R.  I.,  N.  C.,  S.  C.,  Ala.,  White  Lind  (W.  Va.). 

Minn.,  La.,  111.).  Wickup  (Mass.). 

Black   or   Smooth-leaved   Lime- 
tree  (Tenn.). 

LOCALITIES. 

New  Brunswick  to  Georgia,  westward  intermittently  to  Manitoba  and 
Texas.  A  wide  range. 

FEATURES  OP  TREE. 

Sixty  to  ninety  feet  in  height;  two  to  four  feet  in  diameter;  occasionally 
larger;  large  smooth  leaves;  fragrant  flowers,  borne  on  slender,  leaf -like 
structures. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  or  reddish  brown ;  thick  sap  wood  nearly  similar;  very 
straight  and  close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  easily  worked,  and  tough;  not  strong  or  durable. 

REPRESENTATIVE  USES  OF  WOOD. 

Sides  and  backs  of  drawers,  bodies  of  carriages,  woodenware,  and  paper- 
pulp.1 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

1,190,000. 
MODULUS  OF  RUPTURE. 

8,300. 
REMARKS. 

Parts  of  the  inner  bark  have  occasionally  been  utilized  for  cordage.  The 
fragrant  flowers  attract  bees.  The  wood  of  the  White  Basswood  (Tilia 
heterophylld]  is  not  distinguished  from  that  of  the  Common  Basswood 
by  dealers. 

!See  also  "Basswood,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  63,  1907). 


BROADLEAF  TRUNKS  AND  WOODS  177 

WILLOW 

Salix 

The  willows  grow  in  many  places  on  both  hemispheres. 
North  Americans  value  the  fast-growing,  characteristically 
shaped  trees;  while  Europeans  value  the  woods.  The  principal 
experience  with  the  wood  of  the  Willow  has  been  gained  in 
Europe.  The  wood  is  light,  tough,  easily  worked,  and  elastic. 
It  resists  splintering,  stands  well  against  abrasion,  and  in  Europe 
is  used  for  friction-brake  linings,  lapboards,  cricket  bats,  keels 
and  paddles,  Willow  charcoal  ignites  readily  and  for  this  reason 
is  used  in  gunpowder.  Willow  rods  are  used  in  basket-making.1 

In  the  United  States  Willow  trees  are  used  to  protect  and  some- 
times, by  creating  eddies,  to  recover  land  from  water  encroach- 
ment. Saplings  up  to  three  or  four  inches  in  diameter  are  used 
in  river  improvements.  These  saplings  are  made  into  mattresses 
which  are  placed  along  the  banks  of  streams  to  prevent  scour. 
Some  of  the  mattresses  thus  constructed  for  Mississippi  River 
improvement  work  are  three  hundred  feet  wide  and  one  thousand 
feet  long.2  Saplings  are  known  as  " Osiers"  and  are  regularly 
cultivated  in  Europe. 

The  term  Osier  Willow  is  sometimes  applied  to  trees  that  yield 
strong,  slender  shoots.  The  true  Osier,  Sandbar,  or  Longleaf 
Willow  (Salix  fluviatilis)  grows  in  many  places  from  the  Arctic 
Ocean  southward  to  Mexico.  The  White,  Crack,  Bedford,  and 
Goat  Willows  (Salix  alba,  Salix  fragilis,  Salix  russeliana,  and 
Salix  caprea)  are  said  to  afford  good  woods. 

1  See  also  "The  Basket  Willow"  (United  States  Forest  Service,  Bulletin 
No.  46);  "Production  and  Consumption  of  Basket  Willows  in  the  United 
States,  etc.,"  Mell  (United  States  Forest  Service,  Circular  No.  155,  1909); 
"Basket  Willow  Culture,"  Lamb  (United  States  Department  of  Agriculture, 
Farmers"  Bulletin  No.  622,  1914);  "Willows:  Their  Growth,  Use,  and  Im- 
portance," Lamb  (United  States  Forest  Service,  Bulletin  No.  316,  1915). 
"The  Willows:  Identification  and  Characteristics,"   Detwiler,    (American 
Forestry,  January,  1917). 

2  "Bank  Revetment  on  the  Lower  Mississippi,"  Coppee  (Transactions 
American  Society  of  Civil  Engineers,  Vol.  35,  p.  198);  "Erosion  of  River 
Banks  on  the  Mississippi  and  Missouri  Rivers,"  Ockerson  (Transactions 
American  Society  of  Civil  Engineers,  Vol.  38,  p.  396). 


178  ORGANIC  STRUCTURAL  MATERIALS 

Black  Willow.  Salix  nigra  Marsh 

NOMENCLATURE  (Sudworth).  Willow  (N.  Y.,  Pa.,  N.  C.,  S.  C., 

Black  Willow  (local  and  common  Miss.,     Tex.,     Cal.,     Ky.,     Mo., 

name).  Neb.). 
Swamp  Willow  (N.  C.,  S.  C.). 

LOCALITIES. 

New  Brunswick  to  Florida,  westward  intermittently  to  the  Dakotas, 
Arizona,  California,  and  Mexico ;  grows  best  on  bottom  lands  and  along 
the  borders  of  rivers. 

FEATURES  OP  TREE. 

Forty  to  fifty  feet  in  height;  two  to  four  feet  in  diameter;  long,  narrow 
leaves;  a  characteristic  appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  brown ;  sap  wood  nearly  white ;  close-grained. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  light,  and  weak;  checks  badly  in  drying;  readily  worked;  dents  with- 
out splitting. 

REPRESENTATIVE  USES  OF  WOOD. 
Lap-boards,  basket-making,  fuel,  and  charcoal. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

27. 
MODULUS  OF  ELASTICITY. 

550,000. 
MODULUS  OF  RUPTURE. 

6,000. 
REMARKS. 

Many  species  and  varieties  of  Willow  trees  grow  in  the  United  States,  but 
none  of  them  yield  wood  that  is  used  to  any  extent  in  construction. 
Willow  rods,  either  whole  or  split,  are  used  by  basket  makers.  It  is 
said  that  sap-peeled  rods  retain  their  light  color,  and  that  steamed  rods 
turn  yellow.  The  European  uses  of  Willow  wood  have  been  referred  to. 


The  White  Willow  (Salix  alba},  which  has  been  naturalized  in  North  Amer- 
ica, is  hardy,  even  when  located  in  dry  places.  On  the  prairies,  this  tree  is 
sometimes  used  as  a  wind-break.  Trees  planted  several  feet  apart  serve  as 
fence-posts  to  support  barbed  wire. 


BROADLEAF  TRUNKS  AND  WOODS  179 


CATALPA 

Catalpa 

Catalpa  trees  grow  in  the  eastern  part  of  the  United  States,  in 
the  West  Indies,  and  in  some  parts  of  China.  The  Common 
Catalpa  (Catalpa  catalpa)  and  the  Hardy  Catalpa  (Catalpa 
speciosa)  are  natives  of  North  America.  The  name  of  the  genus 
is  that  which  was  given  to  one  of  these  species  by  the  Cherokee 
Indians. 

Until  recently  the  Catalpas  have  attracted  but  little  attention. 
But  they  are  now  regarded  with  interest,  because,  when  the  right 
conditions  prevail,  the  trees  grow  rapidly  and  yield  woods  that 
can  be  used  in  construction.  Catalpa  trees  have  reached  a 
thickness  of  as  much  as  sixteen  inches  in  seventeen  years.  The 
wood  is  soft,  weak,  brittle,  clean,  smooth-grained,  and  very 
durable.  Von  Schrenk  believes  that  the  final  disintegration  of 
this  wood  will  not  be  due  to  attacks  from  fungi,  since  no  fungus 
has  yet  been  found  that  will  grow  in  dead  Catalpa  lumber.  The 
wood  is  attractive  in  appearance  and  is  suitable  for  some  forms  of 
interior  finish  as  well  as  for  carpentry.  Catalpa  posts  and  poles 
are  highly  valued,  but  railway  ties  of  this  wood  do  not  stand  well 
under  heavy  traffic.  The  supply  of  Catalpa  wood  thus  far  is 
limited. 

Catalpa  trees  may  be  known  by  their  flowers  and  by  their  long 
beans,  which  are  sometimes  known  as  smoking-beans.1 


1  The  Forester,  October,  1900,  and  November,  1902.  Forestry  Quarterly, 
vol.  iii,  N.  Y.  "An  Experiment  in  Western  Catalpa."  (Report  of  the  Penn- 
sylvania Dept.  of  Forestry  for  1910-11.)  "Hardy  Catalpa,"  Hall  and  von 
Schrenk  (United  States  Forestry  Bureau,  Bulletin  No.  37). 


180  ORGANIC  STRUCTURAL  MATERIALS 

Catalpa,  Hardy  Catalpa.  Catalpa  speciosa  Warder 

NOMENCLATURE  (Sudworth). 

Catalpa  (R.  I.,  N.  Y.,  La.,  111.,  Western   Catalpa   (Pa.,   Ohio,   la., 

Ind.,  Mo.,     Wis.,     la.,     Neb.,  Neb.,  111.). 

Minn.).  Cigar  Tree  (Mo.,  la.). 

Hardy  Catalpa   (111.,  la.,  Kan.,  Indian  Bean,  Shawneewood  (Ind.). 

Mich.).  Bois  Puant  (La.). 

LOCALITIES. 

Central  Mississippi  Valley,  naturalized  in  many  localities. 

FEATURES  OP  TREE. 

Forty  to  sixty  feet  or  more  in  height;  three  to  six  feet  in  diameter;  well- 
formed  trunk;  large,  white,  faintly  mottled  flowers;  long  pods  or  beans. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heartwood  brown;  thin  sapwood  lighter,  nearly  white;  coarse- 
grained; compact  structure;  annual  layers  clearly  marked ;  an  attract- 
ive wood. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  not  strong,  but  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Railway  ties,  fence-posts,  and  rails;  can  be  used  in  cabinet-work  and 
interior  finish. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

25. 
MODULUS  OF  ELASTICITY. 

1,160,000. 
MODULUS  OF  RUPTURE. 

9,000. 
REMARKS. 

Catalpa  trees  are  not  seriously  injured  by  occasional  inundations,  and,  for 
this  reason,  are  sometimes  planted  along  streams.  Under  the  right 
conditions,  they  grow  rapidly,  and  are  sometimes  used  in  landscape 
effects.  As  a  rule,  the  trunks  of  the  Hardy  Catalpa  are  better  formed 
than  those  of  the  Catalpa. 


Paulownia  (Paulownia  tomentosa).  This  tree  is  a  native  of  Asia,  but  is 
now  cultivated  in  some  of  the  Central-Atlantic  and  Southern  States.  It 
has  catalpa-like  leaves,  which  are  preceded  by  large  pale  blue  or  violet 
flowers  and  followed  by  woody,  capsule-like  fruit  that  in  form  suggests 
hickory  nuts.  The  species,  which  is  of  small  importance,  is  not  related  to 
the  Catalpa,  but  is  sometimes  confused  with  it. 


BROADLEAF  TRUNKS  AND  WOODS  181 

P  ,  .  |  Catalpa  catalpa  (Linn.)  Karst 

\  Catalpa  bignonioides  Walt. 

NOMENCLATURE  (Sudworth). 

Catalpa  (local  and  common  name).  Indian  Bean  (Mass.,  R.  I.,  N.  Y., 

Indian  Cigar  Tree  (Pa.).  N.  J.,  Pa.,  N.  C.,  111.). 

Smoking  Bean  (R.  I.).  Catawba,    Catawba   Tree    (Del., 

Cigar  Tree  (R.  I.,  N.  J.,  Pa.,  W.  Va.  W.  Va.,  Ala.,  Fla.,  Kan.). 

Mo.,  111.,  Wis.,  la.).  Beantree  (N.  J.,  Del.,  Pa.,   Va., 

La.,  Neb.). 

LOCALITIES. 

Native  only  in  the  Gulf  States,  but  naturalized  in  many  localities  east  of 
the  Rocky  Mountains. 

FEATURES  OF  TREE. 

Thirty  to  fifty  feet  in  height;  one  to  two  or  more  feet  in  diameter;  often 
the  trunks  are  not  well  formed;  low,  wide  trees,  with  large  heart- 
shaped  leaves  and  characteristic  flowers;  long  slender  pods  or  beans; 
distinguished  from  the  Hardy  Catalpa  by  the  fact  that  the  flowers  are 
smaller  and  in  denser  clusters. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heartwood  is  light  pink  brown;  the  thin  sapwood  is  nearly  white; 
coarse-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light,  soft,  not  strong,  but  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 
Fence-posts,  railway  ties,  etc. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

27. 
MODULUS  OF  ELASTICITY. 

960,000. 
MODULUS  OF  RUPTURE. 

8,300. 
REMARKS. 

These  trees  grow  rapidly,  but  the  wood  is  less  desirable  than  that  obtained 
from  the  Hardy  Catalpa  (Catalpa  speciosa).  The  long  pods  which 
remain  on  the  trees  after  the  leaves  have  disappeared,  are  sometimes 
used  locally  as  cigars. 


182  ORGANIC  STRUCTURAL  MATERIALS 

MULBERRY 

Morus 

Two  species  of  Mulberry  grow  in  North  America,  and  a  few 
others  grow  abroad.  Of  these,  the  most  valuable  is  the  White 
Mulberry  (Morus  alba),  a  native  of  northern  China  and  Japan, 
which  is  now  also  cultivated  in  many  other  countries  for  its 
leaves  which  form  the  best  food  for  silkworms.  The  Red  Mul- 
berry (Morus  rubra)  and  the  Mexican  Mulberry  (Morus  celtidi- 
folia)  are  the  species  that  are  native  to  the  United  States. 

The  American  species  yield  fairly  hard,  rather  heavy,  and 
quite  durable  woods  that  are  sometimes  used  in  cooperage, 
flumes,  boats,  and  fences. 

White,  Red,  and  Black  Mulberry  trees  may  be  distinguished 
from  one  another  by  the  color  of  their  sweet  berries. 


Red  Mulberry,  Mulberry.     Morus  rubra  Linn. 

NOMENCLATURE  (Sudworth). 

Red  Mulberry,    Mulberry   (local         Virginia  Mulberry  Tree  (Term.). 

and  common  names).  Murier  Sauvage  (La.). 

Black  Mulberry  (N.  J.,  Pa.,  W.Va.). 

LOCALITIES. 

Massachusetts  to  Florida,  westward  intermittently  to  Nebraska  and 
Texas;  best  in  lower  Ohio  and  Mississippi  River  basins. 

FEATURES  OF  TREE. 

Fifty  to  sixty  feet  in  height;  two  and  one-half  to  three  feet  in  diameter; 
sweet,  edible  fruit;  the  leaves  are  very  variable,  sometimes  entire,  but 
often  three-lobed;  dark  brown  broken  bark;  smooth  gray  branches.- 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heartwood,  light  orange  yellow;  thin  sapwood  whitish;  coarse- 
grained; compact  structure;  the  annual  layers  are  clearly  marked. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  not  strong,  but  very  durable  in  contact  with  the  soil;  it  re- 
ceives a  good  polish. 

REPRESENTATIVE  USES  OF  WOOD. 
Fencing,  cooperage,  etc. 

WEIGHT  OF  SEASONED  WOODS  IN  POUNDS  PER  CUBIC  FOOT. 

36. 
MODULUS  OF  ELASTICITY.  MODULUS  OF  RUPTURE. 

11,700,000.  11,000. 

REMARKS. 

An  ornamental  tree. 


BROADLEAF  TRUNKS  AND  WOODS  183 

HORSE  CHESTNUT.     BUCKEYE 

Aesculus 

Horse  Chestnut  trees  (Aesculus  hippocastanum) ,  supposed  to 
be  natives  of  Asia,  have  long  been  among  the  most  popular  shade 
trees  of  Europe  and  North  America.  The  Buckeyes  (Aesculus 
glabra,  Aesculus  octandra,  and  Aesculus  californica)  grow  from 
Ohio  and  southern  Iowa,  southward  to  northern  Georgia  and 
northern  Louisiana,  and  in  California.  The  name  "  Horse  Chest- 
nut" is  probably  due  to  an  ironical  reference  to  the  coarse  nuts, 
while  the  name  " Buckeye"  refers  to  the  appearance  of  the  nut 
of  that  tree  which,  under  certain  conditions,  suggests  the  eye  of 
the  deer. 

Horse  Chestnut  and  Buckeye  woods  resemble  one  another,  in 
that  both  are  soft,  straight-grained,  and  easily  worked.  They 
decay  rapidly  when  exposed  to  the  weather.  The  woods  are 
sometimes  employed  in  artificial  limbs,  splints,  woodenware,  and 
paper  pulp. 

Both  trees  may  be  known  by  their  nuts,  which  are  enclosed  in 
prickly  husks.1 


also  "Trees  of  Northern  States  and  Canada,"  Hough,  page  338. 


184  ORGANIC  STRUCTURAL  MATERIALS 

Ohio  Buckeye,  Fetid  Buckeye.  Aesculus  glabra  Willd. 

NOMENCLATURE  (Sudworth). 

Buckeye,    Ohio    Buckeye    (local         Stinking  Buckeye  (Ala.,  Ark.). 

and  common  names).  American  Horse  Chestnut  (Pa.). 

Fetid  Buckeye  (W.  Va.). 

LOCALITIES. 

Ohio  River  basin  to  Alabama,  portions  of  Iowa,  Kansas,  and  Oklahoma. 

FEATURES  OP  TREE. 

Twenty-five  to  forty-five  feet  in  height;  one  to  one  and  one-half  feet  in 
diameter;  the  yellowish-white  flowers  are  succeeded  by  round  prickly 
pods  which  contain  nuts. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heart  wood  white;  sap  wood  a  little  darker;  close-grained;  frequent  dark 
lines  of  decay. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Weak,  light,  and  soft,  but  hard  to  split. 

REPRESENTATIVE  USES  OP  WOOD. 

Artificial  limbs,  wooden  ware,  and  paper-pulp;  rarely  lumber. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28. 
MODULUS  OF  ELASTICITY. 

910,000. 
MODULUS  OF  RUPTURE. 

7,000. 
REMARKS. 

The  nearly  similar  Horse  Chestnut  (Aesculus  hippocastanum)  is  not  native, 
but  is  largely  planted  in  North  America.  It  is  from  forty  to  fifty  or 
more  feet  in  height,  and  is  from  two  to  sometimes  four  feet  in  di- 
ameter. The  Horse  Chestnut  tree  is  one  of  the  most  popular  of  all 
shade  trees.  The  light,  weak  wood  is  seldom  used. 


BROADLEAF  TRUNKS  AND  WOODS  185 

f  Aesculus  octandra  Marsh 
Buckeye,  Sweet  Buckeye.  7/7        *  •. 

{ Aesculus  flava  Ait. 

NOMENCLATURE  (Sudworth). 

Buckeye  (N.  C.,  S.  C.,  Ala.,  Miss.,        Yellow  Buckeye  (S.  C.,  Ala.). 

La.,  Tex.,  Ky.).  Large  Buckeye,  Big  Buckeye  (Tex. 

Sweet  Buckeye   (W.   Va.,   Miss.,  Tenn.). 

Tex.,  Mo.,  Ind.). 

LOCALITIES. 

Alleghany  Mountains,  Pennsylvania  to  Georgia,  westward  intermittently 
to  Iowa  and  Texas. 

FEATURES  OF  TREE. 

Forty  to  seventy  feet  in  height;  one  to  three  feet  in  diameter;  sometimes 
a  low  shrub ;  the  pods  are  distinguished  from  those  of  the  Ohio  Buckeye 
(Aesculus  glabra)  by  the  fact  that  they  are  smooth. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  creamy  white;  sapwood  similar;  compact  structure;  close- 
grained;  difficult  to  split. 

REPRESENTATIVE  USES  OF  WOOD. 

Similar  to  those  of  the  Ohio  Buckeye  (Aesculus  glabra). 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

26.64. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 

REMARKS. 

The  California  Buckeye  or  California  Horse  Chestnut  (Aesculus  calif or- 
nica),  grows  along  the  Pacific  Coast  from  Mount  Shasta,  southward 
to  Los  Angeles.  It  is  often  quite  small,  but  in  some  localities  is  from 
thirty  to  forty  feet  in  height.  The  soft,  light,  compact,  close-grained, 
ivory-white  wood  could  probably  be  employed  in  turnery. 


186  ORGANIC  STRUCTURAL  MATERIALS 

GUM 

Liquidambar,  Nyssa 

This  name  applies  to  a  number  of  trees  that  lie  within  at  least 
two  genera.  One  genus  (Liquidambar)  contributes  about  four 
species,  which  grow  in  many  places  in  the  eastern  part  of  the 
United  States  and  parts  of  Mexico,  Central  America,  and  Asia; 
while  the  other  genus  (Nyssd)  includes  five  species  which  grow 
only  in  the  eastern  part  of  the  United  States  and  in  the  southern 
part  of  Asia.1 

The  wood  of  the  Red  or  Sweet  Gum  (Liquidambar  styraciflua) 
is  about  as  strong  and  stiff  as  that  of  the  chestnut.  It  is  brittle, 
straight-grained,  rather  fine  and  dense,  absorbent,  liable  to  warp 
and  twist  in  seasoning,  fairly  heavy,  and  moderately  soft.  Its 
natural  color  is  attractive,  but  this  is  often  changed  by  staining, 
so  as  to  resemble  the  colors  of  other  woods.  Some  pieces  of  Red 
Gum  resemble  walnut  and  these  are  usually  cut  into  veneers 
which  are  sometimes  misleadingly  sold  under  such  names  as 
" California  Red  Gum,"  "Hazel,"  " Satin  Walnut,"  and  even 
"  Circassian  Walnut."  Ordinary  pieces  are  sparingly  used  for 
many  purposes,  as  railway  ties,  carpentry,  flooring,  furniture, 
paving  blocks,  packing  boxes,  barrel  staves,  pulley-facing,  coffin 
boards,  and  woodenware.  The  trees,  which  are  very  attractive 
and  which  are  prized  in  landscape  effects,  bear  rough  fruiting 
heads  or  balls  about  as  large  as  the  fruiting  heads  of  the  syca- 
more. Their  pointed,  star-shaped  leaves  exhibit  bright  scarlet 
and  purple  tints  during  the  autumn. 

The  wood  of  the  Water  Gum  or  Tupelo  Gum  (Nyssa  aquatica) 
is  often  marketed  with  that  of  the  Red  Gum.  This  wood  is 
light,  strong,  tough,  fine-grained,  easily  glued,  and  comparatively 
cheap.  Its  cellular  arrangement  is  complicated  and  the  wood  is 
correspondingly  hard  to  split  and  work.  The  heartwood  varies 
in  color  from  dull  gray  to  dull  brown,  while  the  color  of  the  sap- 
wood  resembles  that  of  ordinary  poplar.  After  seasoning,  it  is 
often  hard  to  distinguish  between  the  sapwood  of  the  better 
grades  of  Tupelo  Gum  and  ordinary  poplar.  This  wood  is  also 
sold  under  other  names,  as  "Bay  Poplar,"  and  "Circassian  Wal- 
nut," and  is  used  for  packing  boxes,  furniture,  the  backs  of 
drawers,  and  house-trim.  The  trees,  which  often  grow  in  deep 
swamps  and  along  the  margins  of  water  courses,  bear  leaves 


BROADLEAF  TRUNKS  AND  WOODS  187 

which  exhibit  beautiful  purple  and  reddish  tints  in  the  autumn. 
The  Sour  Gum  or  Black  Gum  (Nyssa  sylvatica)  yields  a  rather 
soft,  light,  tough,  fine,  but  irregularly  grained  wood,  which  is 
hard  to  split  and  work,  and  which  is  used  for  wheel-hubs,  rollers, 
woodenware,  thin  lumber,  and  fruit  crates.  The  Sour  Gum  tree 
grows  in  swamps  and  hardwood  bottoms.  Its  range  is  greater 
than  that  of  the  others,  but  the  Sour  Gum  forms  a  much  less 
important  part  of  the  forest. 


1  See  also  "The  Red  Gum"  Chittenden  and  Hatt  (United  States  Forest 
Service,  Bulletin  No.  58,  1906),  "The  Utilization  of  Tupelo,"  Holroyd 
(United  States  Forest  Service,  Circular  No.  40,  1906),  "Distinguishing 
Characteristics  of  North  American  Gumwoods,"  Sudworth  and  Mell  (United 
States  Forest  Service,  Bulletin  No.  103,  1911),  ''The  Red  Gum"  Detwiler 
(American  Forestry,  November,  1916). 


188  ORGANIC  STRUCTURAL  MATERIALS 

Gum,  Sweet  Gum,  Red  Gum.         Liquidambar  styraciflua  Linn. 

NOMENCLATURE  (Sudworth). 

Gum,    Sweet    Gum,    Red    Gum         Gum  Tree  (Va.,  S.  C.,  La.). 

(local  and  common  names).  Alligatorwood,  Blisted,  (N.  J.). 

Liquidambar  (R.  I.,  N.  Y.,  Del., 
N.  J.,  Pa.,  La.,  Tex.,  Ohio,  111.). 

LOCALITIES. 

Connecticut  to  Florida,  westward  intermittently  to  Illinois,  Texas,  and 
.  .   Mexico;  best  development  in  basin  of  Mississippi  River. 

FEATURES  OF  TREE. 

Eighty  to  one  hundred  or  more  feet  in  height;  three  to  five  feet  in  diameter; 
a  tall,  straight  trunk;  corky  ridges  are  frequent  on  the  branches;  the 
star-shaped  leaves  turn  to  brilliant  scarlet  in  the  autumn;  there  are 
round  balls  on  long  stems. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  rich  brown,  suggests  Black  Walnut;  sapwood  nearly  white; 
close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

About  as  strong  and  stiff  as  Chestnut  ;l  heartwood  is  durable  when  exposed ; 
wood  shrinks  and  warps  badly  if  seasoned  by  ordinary  methods,  but 
responds  to  special  methods;  glues  and  paints  well;  holds  spikes  well; 
receives  a  high  polish;  tasteless. 

REPRESENTATIVE  USES  OF  WOOD. 

Veneers,  cabinet-work,  packing  boxes,  carpentry,  shingles,  clapboards, 
paving-blocks,  wooden  plates,  and  barrel  staves. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
37  (United  States  Forestry  Division). 
36. 

MODULUS  OF  ELASTICITY. 

1,700,000  (average  of  118  tests  by  United  States  Forestry  Division).2 
1,220,000. 

MODULUS  OF  RUPTURE. 

9,500  (average  of  118  tests  by  United  States  Forestry  Division).2 
9,200. 

REMARKS. 

The  wood  has  other  commercial  names  as  "Hazel,"  "Satin  Walnut," 
"Star-leaved  Gum."  Clear  wood  can  be  obtained  in  boards  of  large 
size.  The  larger  trees  often  have  hollow  butts. 


1  Woodward,  reported  Gum  ties  as  good  after  five  years  of  service  on  the 
Texas  &  Pacific  Railroad. 

2  See  p.  33. 


BROADLEAF  TRUNKS  AND  WOODS  189 

Tupelo  Gum,  Cotton  Gum,  Large  Tupelo.  Nyssa  aquatica  Linn. 

NOMENCLATURE  (Sudworth). 

Tupelo  Gum,  Cotton  Gum,  Large  Tupelo,    Swamp    Tupelo     (N.     C. 

Tupelo     (local     and    common  S.  C.,  La.). 

names).  Olivetree,    Wild    Olivetree     (Miss. 

Sour  Gum  (Ark.,  Mo.).  La.). 

LOCALITIES. 

Virginia  and  Kentucky,  southward  and  westward  to  Missouri  and  Texas. 

FEATURES  OF  TREE. 

Sixty  to  eighty  feet  in  height;  two  to  three  feet  in  diameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown,  often  nearly  white;  sapwood  nearhr  the  same. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  light,  not  strong;  close,  compact  grain;  difficult  to  work. 

REPRESENTATIVE  USES  OF  WOOD. 

Turnery,  woodenware,  boxes,  and  fruit-crates;  pieces  of  the  root  are  some- 
times used  to  float  nets. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

32. 
MODULUS  OF  ELASTICITY. 

730,000. 
MODULUS  OF  RUPTURE. 

9,300. 
REMARKS. 

These  trees  grow  on  rich  bottom  lands  and  in  deep  swamps.  They  are 
often  associated  with  cypress  trees.  The  specific  name  is  due  to  the 
fact  that  the  trees  tolerate  quantities  of  water.  The  butts  of  large 
trees  are  usually  hollow,  while  the  parts  above  are  usually  sound. 


The  Sour  Gum  (Nyssa  ogeche)  grows  along  the  Atlantic  Coast  from  South 
Carolina  to  Northern  and  Western  Florida.  The  trees,  which  are  usually 
found  on  wet  lands,  attain  heights  of  from  thirty  to  fifty  feet.  The  soft, 
compact,  weak,  brownish  heartwood  is  hardly  distinguishable  from  the 
brownish  sapwood.  The  tree  is  also  known  as.Ogeechee  Lime,  Wild  Lime- 
tree,  Limetree,  Tupelo,  Sour  Tupelo,  and  Gopher  Plum. 


190  ORGANIC  STRUCTURAL  MATERIALS 

Sour  Gum,  Black  Gum,  Tupelo.  (  "yssa  sylv^a  " 

{  Nyssa  multiflora  Wang. 

NOMENCLATURE  (Sud worth). 

Sour  Gum,  Black  Gum,  Tupelo  Wild  Pear  Tree,  Yellow  Gum  Tree 

(local  and  common  names).  (Tenn.). 

Pepperidge    (Vt.,    Mass.,    R.   I.,  Gum  (Md.). 

N.  Y.,  N.  J.,  S.  C.,  Tenn.,  Mich.,  Stinkwood  (W.  Va.). 

Ohio,  Ontario).  Tupelo  Gum  (Fla.). 

LOCALITIES. 

Ontario  and  Maine  to  Florida,  westward  intermittently  to  Michigan  and 
Texas. 

FEATURES  OF  TREE. 

Forty-five  to  one  hundred  feet  in  height;  several  inches  to  occasionally 
four  feet  in  diameter;  ovoid,  bluish  black,  sour  fruit,  with  ribbed  seed; 
horizontal  branches;  short,  spur-like  lateral  branchlets. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  brown  or  yellow,  often  nearly  white;  the  sapwood  is 
hardly  distinguishable;  fine-grained;  interwoyen  cell-structures. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong,  tough,  not  hard;  the  cell-structures  are  interlaced,  and  for  this 
reason  the  wood  checks  unless  it  is  carefully  seasoned;  it  is  hard  to 
work. 

REPRESENTATIVE  USES  OF  WOOD. 

Wagon-hubs,  rollers,  and  ox-yokes;  wooden  ware,  such  as  bowls  and  shoes; 
thin  lumber  is  used  for  boxes  and  crates;  selected  pieces  used  in  cabinet 
work. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

39. 
MODULUS  OF  ELASTICITY. 

1,160,000. 
MODULUS  OF  RUPTURE. 

11,800. 
REMARKS. 

These  trees  grow  on  hillsides  and  along  the  borders  of  swamps  and  water- 
ways. Large  trees  are  often  hollow  near  the  ground.  The  wood  has  a 
limited  field  of  usefulness  because  it  is  so  hard  to  work. 


BROADLEAF  TRUNKS  AND  WOODS  191 

HOLLY  BOXWOOD  LIGNUMVIT^ 

Ilex  Buxus,  Cornus,  etc.   .  Guajacum 

These  trees  yield  small  but  very  perfect  pieces  of  wood  that 
fill  needs  for  which  no  other  woods  seem  equally  fitted. 

Holly  trees  (Ilex  opaca)  grow  along  the  coast  in  the  United 
States  from  Quincy,  Massachusetts,  to  Louisiana,  and  in  the 
interior,  in  parts  of  Missouri,  Illinois,  Kentucky,  Tennessee,  and 
Arkansas.  The  wood,  which  is  noted  for  its  fine  even  grain  and 
its  smooth,  ivory-white  color,  is  used  for  carvings,  decorations, 
and  inlaid  work,  where  fine  qualities  and  white  effects  are  re- 
quired. The  European  source  is  the  Holly  (Ilex  aquifolium). 
Holly  trees  are  noted  for  their  brilliant  evergreen  foliage  and 
bright  red  berries,  that  have  long  been  associated  with  the  Christ- 
mas season. 

The  true  Boxwood  (Buxus  sempervirens)  becomes  a  tree  in 
some  parts  of  Europe,  Asia,  and  northern  Africa,  but,  in  the 
United  States,  is  generally  a  small  shrub  that  is  useless,  save  in 
landscape  effects.  The  wood  is  noted  for  its  fine,  firm,  even 
texture  and  is  used  for  carvings  and  mathematical  instruments. 
No  other  wood  is  better  for  wood  engravings.  Boxwood  is  often 
hard  to  season.  It  is  said  that  French  engravers  place  pieces 
designed  for  their  finest  work  in  dark  cellars  as  soon  as  they  are 
cut,  and  that  they  keep  them  in  such  surroundings  for  several 
years  before  they  are  used.  American  Boxwood  is  derived  from 
the  Flowering  Dogwood  (Cornus  florida)  and  from  several  other 
species. 

The  Lignum vitaes  (Guajacum  sanctum  and  Guajacum  officinale) 
grow  in  Florida,  the  West  Indies,  Colombia,  and  Venezuela,  and 
yield  wood  that  is  noted  for  great  weight,  strength,  complicated 
cellular  structure,  and  durability.  Under  the  axe,  it  may  be  said 
to  crumble  rather  than  to  split.  It  contains  a  resin  (Guajac)  that 
is  sometimes  used  in  medicine  and  as  a  lubricant.  The  wood  is 
used  for  rollers,  pulley  sheaves,  tool  handles,  and  sometimes  in 
place  of  bearing  metals  in  parts  of  marine  engines.  Some 
lignum  vitse  ties,  removed  from  the  Panama  Railway  after  more 
than  thirty  years  of  service,  because  they  were  too  small  to 
afford  proper  bearings  for  the  rails,  were  still  in  good  condition. 


192  ORGANIC  STRUCTURAL  MATERIALS 

Holly,  American  Holly.  Ilex  opaca  Ait. 

NOMENCLATURE  (Sudworth). 

Holly,     American    Holly     (local         White  Holly  (Va.). 
and  common  names). 

LOCALITIES. 

Maine  to  Florida,  westward  intermittently  to  Indiana  and  Texas. 

FEATURES  OF  TREE. 

Occasionally  fifty  feet  in  height  and  three  feet  in  diameter,  but  frequently 
much,  smaller,  particularly  in  the  North ;  the  spiny-margined  evergreen 
,   leaves  are  of  a  bright  green  color;  the  bright  red  berries  remain  until  the 
spring. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  cream  white,  darkening  or  spotting  on  exposure;  sapwood 
similar  or  lighter;  very  close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Tough,  moderately  hard  and  heavy,  easily  worked. 

REPRESENTATIVE  USES  OF  WOOD. 

Inlaid  work,  carvings,  scrollwork,  and  turnery;  moderately  used  for  furni- 
ture and  decoration. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

36. 
MODULUS  OF  ELASTICITY. 

910,000. 
MODULUS  OF  RUPTURE. 

9,700. 
REMARKS. 

The  wood  suggests  ivory,  and  is  characteristically  employed  for  the 
white  of  inlaid  work.  The  more  elaborate  specimens  of  inlaid  work  are 
manufactured  in  Italy,  but  are  not  always  durable  when  brought  into 
highly  heated  houses  in  the  United  States.  Inlaid  work  manufactured 
in  the  United  States  may  be  less  elaborate  than  the  foreign  product, 
but  it  is  often  more  durable. 


BROADLEAF  TRUNKS  AND  WOODS  193 


(  Cornus  florida  Linn. 
Dogwood,  Flowering  Dogwood.  |  Cynoxylon 


NOMENCLATURE  (Sudworth).  False  Box-dogwood  (Ky.). 

Dogwood,    Flowering    Dogwood  New  England  Boxwood  (Tenn.). 

(local  and  common  names).  Cornel,    Flowering    Cornel    (Tex., 
Boxwood   (Conn.,  R.  I.,  N.  Y.,  R.  I.). 

Mich.,  Ky.,  Ind.,  Ont.). 

LOCALITIES. 

Ontario  and  New  England  to  Florida,  westward  intermittently  to  Minne- 
sota and  Texas;  also  found  in  the  Sierra  Madre  Mountains  and  in 
Mexico. 

FEATURES  OF  TREE. 

Twenty-five  to  thirty-five  feet  in  height;  one  foot  or  more  in  diameter; 
often  a  low  shrub;  large,  white  flower-like  bracts  precede  the  develop- 
ment of  the  true,  but  less  conspicuous,  greenish  flowers  which  precede 
the  leaves;  in  the  fall,  red  berries  are  exhibited;  the  bark  is  rough  and 
dark. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  rich  brown,  changing  to  green  and  red;  sap  wood  lighter; 
close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  strong,  tough,  and  hard;  it  receives  a  high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Wood-carving,  wood-engraving,  bearings  of  machinery,  and  turnery. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

50. 
MODULUS  OF  ELASTICITY. 

1,160,000. 
MODULUS  OF  RUPTURE. 

12,800. 
REMARKS. 

The  Mexican  or  Black  Persimmon,  and  the  Great  Laurel  (Rhododendron 
maximum)  yield  woods  that  are  used  in  place  of  Dogwood.  The  Yellow- 
wood  (Schcefferia  frutescens},  which  is  found  in  Florida,  also  yields 
wood  that  is  known  as  Boxwood.  The  names  Dogwood  and  Poison 
Dogwood  are  sometimes  applied  to  the  Sumach. 


194  ORGANIC  STRUCTURAL  MATERIALS 

Lignumvitae.  Guajacum  sanctum 

NOMENCLATURE  (Sudworth). 
Lignumvitae  (Fla.).  Ironwood  (Fla.). 

LOCALITIES. 

Semitropical  Florida,  the  Bahamas,  San  Domingo,  Cuba,  Puerto  Rico, 
Jamaica  and  Yucatan. 

FEATURES  OF  TREE. 

Twenty-five  feet  in  height;  one  foot  in  diameter;  a  low,  gnarled  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD.. 

Heartwood  rich  yellow  brown  in  younger  specimens  and  almost  black  in 
older  ones;  sapwood  light  yellow;  close-grained;  compact  structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Very  heavy  and  exceedingly  hard;  strong,  hard  to  work,  and  brittle;  very 
durable;  the  wood  contains  a  resin  which  acts  as  a  lubricant  when  in 
water. 

REPRESENTATIVE  USES  OF  WOOD. 

Rollers,  pulley-sheaves,  and  tool-handles;  bearings  for  parts  under  water. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

71. 
MODULUS  OF  ELASTICITY. 

1,220,000. 
MODULUS  OF  RUPTURE. 

11,100. 
REMARKS. 

Two  other  species  (Guajacum  officinale  and  Guajacum  arboreum)  afford 
similar  woods  which  are  not  distinguished  commercially  from  the  above. 


BROADLEAF  TRUNKS  AND  WOODS  195 

LAUREL 

Magnolia,  Rhododendron,  Arbutus,  etc. 

The  name  Laurel  applies  locally  or  botanically  to  a  number  of 
American  plants,  several  of  which  attain  to  the  dignity  of  trees. 

The  Big  Laurel  or  Magnolia  (Magnolia  fcetida)  grows  naturally 
along  the  Atlantic  Coast  from  North  Carolina  to  Florida,  and 
thence  through  the  Gulf  region  westward  to  Texas.  The  tree, 
which  is  also  cultivated  in  other  localities  with  temperate 
climates,  is  very  beautiful  and  valued  in  landscape  effects,  while 
the  hard,  heavy,  whitish  wood  is  occasionally  used  in  cabinet 
work.  The  California  Laurel  (Umbellularia  calif ornica)  and  the 
Laurel  or  Madrona  (Arbutus  menziesii)  are  Pacific  Coast  species, 
which  yield  strong,  hard,  heavy,  and  attractive  woods  that  are 
sometimes  used  in  furniture.  Sargent1  regards  the  wood  of  the 
former  species  as  the  most  valuable  of  those  produced  in  the 
forests  of  the  Pacific  region  for  interior  finish  and  furniture.  The 
wood  of  the  Great  Laurel  or  Rose  Bay  (Rhododendron  maximum) 
is  hard,  rather  brittle,  close-grained,  and  heavy,  and  is  sometimes 
used  as  a  substitute  for  Boxwood  in  wood  engraving.  The 
gnarled  roots  of  the  Mountain  Laurel  or  Calico  Bush  (Kalmia 
latifolia)  are  occasionally  used  for  rustic  hanging-baskets,  rustic 
seats,  and  the  like. 


ltl  Manual  of  the  Trees  of  North  America,"  Sargent  (Houghton,  Mifflin 
&  Company,  1905,  p.  335). 


196  ORGANIC  STRUCTURAL  MATERIALS 

California  Laurel,  Mountain  Laurel.         Umbellularia  calif ornica  Nutt 

NOMENCLATURE  (Sudworth). 

California       Laurel,        Mountain       Myrtle-tree,     Cajeput,     California 

Laurel  (Cal.,  Nev.).  Olive  (Oreg.). 

California    Bay-tree,     Spice-tree         Californian  Sassafras. 

(Cal.,  Nev.,     Oreg.). 
Laurel,   Bay-tree,  Oreodaphne 

(Cal.). 

LOCALITIES. 

California  and  Oregon. 

FEATURES  OF  TREE. 

Seventy-five  to  one  hundred  feet  in  height;  three  to  five  feet  in  diameter; 
evergreen  foliage;  beautiful  appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  light  rich  brown;  sapwood  lighter  brown;  close-grained;  com- 
pact structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  receives  a  beautiful  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  cabinet-work,  cleats,  and  crosstrees. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

40. 
MODULUS  OF  ELASTICITY. 

1,510,000. 
MODULUS  OF  RUPTURE. 

11,400. 
REMARKS. 

A  valuable  local  cabinet  wood. 


BROADLEAF  TRUNKS  AND  WOODS  197 

Madron  a,  Madrona  Laurel.  Arbutus  menziesii  Pursh. 

NOMENCLATURE  (Sudworth). 

Madrofia,  Madrona  Laurel  (Cal.,  Madrone-tree,    Manzanita    (Oreg., 

Oreg.).  Cal.). 

Laurel,  Laurelwood,  Madrone.  Madrove  (Cal.). 

LOCALITIES. 

Pacific  Coast  from  British  Columbia  to  southern  California. 

FEATURES  OF  TREE. 

Fifty  to  seventy-five  feet  in  height,  occasionally  higher;  two  to  four  feet  in 
diameter;  a  straight,  well-formed  trunk;  evergreen  foliage;  a  shrub  in  the 
South. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heartwood  reddish;  thin  sapwood  slightly  pink;  close-grained; 
numerous  and  conspicuous  medullary  rays. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  hard,  and  strong;  checks  badly  in  seasoning. 

REPRESENTATIVE  USES  OF  WOOD. 

The  charcoal  is  used  in  gunpowder;  the  wood  is  sometimes  used  for 
furniture. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

43. 
MODULUS  OF  ELASTICITY. 

1,190,000. 
MODULUS  OF  RUPTURE. 

12,000. 
REMARKS. 

A  beautiful  ornamental  tree  yielding  attractive  wood  which  is  seldom  used 
save  locally.  The  Madrona  tree  has  been  confused  with  the  Laurel, 
Madrona,  or  Mexican  Madrona  (Arbutus  xalapensis  or  Arbutus  texana), 
also  called  the  Manzanita,  and  with  the  California  species  of  the  genus 
Arctostaphylos  from  which  Manzanita  wood  is  derived. 


The  name  Manzanita  is  somewhat  loosely  used  to  designate  hard,  heavy, 
close-grained,  rich,  reddish-brown  woods,  that  in  California  are  sometimes 
used  for  trinkets,  such  as  cuff  buttons,  checkers,  and  rulers.  Large-sized 
pieces  of  Manzanita  wood  are  rare,  and  long  pieces  are  practically  un- 
known. Probably  most  of  this  wood  is  derived  from  the  Manzanitas  (Arc- 
tostaphylos pungens,  Arctostaphylos  tomentosa,  and  Arctostaphylos  glauca). 


198  ORGANIC  STRUCTURAL  MATERIALS 


SASSAFRAS  CAMPHOR  TREE 

Sassafras  Cinnamomum 

The  Sassafras  grows  in  many  parts  of  the  eastern  half  of  the 
United  States.  It  was  one  of  the  first  of  the  North  American 
trees  to  be  described  in  Europe,  where  at  that  early  date,  many 
fictitious  properties  were  credited  to  the  aromatic  essences  by 
which  it  is  characterized.  The  soft,  light,  brittle,  slightly  aro- 
matic, and  rather  durable  wood  is  occasionally  used  for  buckets 
and  fences.  The  trees  may  be  known  by  their  fragrant,  mucilagi- 
nous leaves,  some  of  which  are  without  lobes,  while  others  have 
lobes  on  one  side,  and  still  others  have  lobes  on  both  sides.  The 
characteristic  sassafras  odor  and  flavor  are  more  or  less  evident 
in  the  wood,  twigs,  and  leaves,  but  are  much  more  pronounced 
in  the  bark  of  the  roots. 

The  Camphor  tree  (Cinnamomum  camphora) ,  which  is  related 
to  the  Sassafras,  has  been  acclimated  in  California,  and,  on  the 
Atlantic  Coast,  from  Charleston  to  Florida.  The  trees,  with 
their  shining,  evergreen  leaves,  are  very  attractive,  and,  in  the 
United  States,  are  valued  in  landscape  work.  The  close-grained, 
aromatic,  yellowish  woods  are  sparingly  used  in  cabinet  work  and 
insect-proof  chests.  In  Asia,  where  this  tree  is  native,  it  is  the 
chief  source  of  commercial  camphor;  but,  in  this  country,  the 
trees,  although  thrifty,  do  not  appear  to  secrete  the  same  quanti- 
ties of  this  resin.  Camphor  is  found  also  in  the  roots  of  the 
Cinnamon  tree  (Cinnamomum  zeylam'cum)  of  India  and  Ceylon. 
The  Cassia  Bark  (Cinnamomum  cassia),  of  Burmah  and  China, 
yields  cassia  but  no  camphor.  Transplanted  specimens  of  the 
two  last-named  trees  have  been  made  to  grow  in  some  parts  of 
California  and  Florida.1 


1  See  also  Dewey  (United  States  Division  of  Botany,  Circular  No.  12, 
Revised). 


BROADLEAF  TRUNKS  AND  WOODS  199 

J  Sassafras  officinale  Nees  and  Eberm. 
Sassafras.  ^  Sassafras  sassafras  (Linn.)  Karst. 

NOMENCLATURE  (Sudworth). 

Sassafras    (local  and  common  Sassafac,  Sassafrac  (W.  Va.,  Del.). 

name).  Gumbo  file  (La.,  negro). 

Saxifrax,     Sasifrax     Tree     (Fla., 

Tenn.). 

LOCALITIES. 

Vermont  to  Florida,  westward  intermittently  to  Michigan  and  Texas. 

FEATURES  OF  TREE. 

Thirty  to  fifty  feet  in  height;  one  to  three  feet  in  diameter,  sometimes 
larger;  often  a  low  shrub;  characteristic  odor;  the  greenish-yellow  flowers 
precede  the  leaves  in  early  spring. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Thick  heartwood  delicate  brown;  thin  sapwood  yellowish-white;  coarse- 
grained; the  annual  rings  are  clearly  marked. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  not  strong,  and  brittle;  checks  in  drying;  very  durable  in  con- 
tact with  the  soil;  the  wood  is  slightly  aromatic. 

REPRESENTATIVE  USES  OF  WOOD. 

Pails,  buckets,  ox-yokes,  fence-posts,  and  rails. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

31. 
MODULUS  OF  ELASTICITY. 

730,000. 
MODULUS  OF  RUPTURE. 

8,500. 
REMARKS. 

The  leaves  and  young  shoots  are  mucilaginous.  The  bark,  leaves,  and 
wood  emit  a  characteristic  odor.  The  bark  of  the  root  is  particularly 
aromatic.  Small  Sassafras  bushes  often  form  thickets. 


200  ORGANIC  STRUCTURAL  MATERIALS 

GREENHEART 

Nectandra 

The  Greenheart  tree  (Nectandra  rodioei),  which  is  a  member  of 
the  Laurel  family,  grows  in  British  Guiana  and  some  adjacent 
parts  of  South  America,  as  well  as  in  the  West  Indies. 

The  wood  is  hard,  strong,  tough,  and  very  heavy.  The 
colors  of  the  heartwood  vary  from  dark  green  to  chestnut  brown, 
selected  pieces  presenting  an  exceptionally  rich  appearance  when 
finished.  The  quality  of  durability,  which  is  partly  due  to  the 
presence  of  an  alkaloid,  known  as  "biberine,"  is  so  remarkable 
that  the  wood  has  earned  a  world-wide  reputation.  Greenheart 
is  one  of  the  best  of  all  construction  timbers  and,  although  seldom 
seen  in  the  United  States,  is  used  abroad  for  docks,  bridges,  keels, 
rollers,  flooring,  wagons,  carriage-shafts,  furniture,  and  belaying- 
pins.  All  of  the  gates,  piers,  and  jetties  of  the  Liverpool  Docks, 
and  the  lock  gates  of  the  Bridge  water  and  Manchester  Canals, 
were  built  of  this  wood.  Pieces  used  in  the  construction  of  the 
Canada  Dock,  which  was  built  in  1856,  were  used  again  in  the 
reconstruction  of  that  work  in  1894.  Greenheart  was  specified 
for  the  sills  and  fenders  of  the  lock  gates  of  the  Panama  Canal. 
The  Antarctic  ship,  Discovery,  and  Nansen's  ship,  The  Fram, 
were  built  of  it.1 


^ee  also  "Greenheart,"  Mell  and  Brush  (United  States  Forest  Service, 
Circular,  No.  211);  "Greenheart  Used  in  Panama  Canal,  etc."  Armstrong 
(Engineering  Record,  Vol.  73,  Nos.  5  and  6,  pp.  149  and  180);  "The  Green- 
heart  of  Commerce,"  Mell  (American  Forestry,  May,  1916). 


BROADLEAF  TRUNKS  AND  WOODS  201 

Greenheart.  Nectandra  rodioei 

NOMENCLATUKE   (Mell  and  Brush).1 
Greenheart  (local  and  common  name). 
Sipiri,  Bebeeru,  Bibiru,  Supeira  (native  Indian  names). 
Torchwood. 

LOCALITIES. 

British,  Dutch,  and  French  Guiana,  some  adjacent  parts  of  South  Amer- 
ica, and  the  West  Indies.  It  is  seldom  found  more  than  fifty  miles,  and 
never  found  more  than  one  hundred  miles,  from  the  coast. 

FEATURES  OF  TREE. 

Twenty-five  to  sometimes  seventy  feet  in  height;  two  to  four  feet  in  di- 
ameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark  green  to  chestnut  brown,  sometimes  nearly  black;  clean; 
straight-grained;  free  from  knots;  some  pieces  possess  great  beauty. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  tough,  elastic,  strong,  and  durable;  repels  termites  and  tere- 
does;  liable  to  split  and  splinter,  and  so  requires  care  in  seasoning  and 
working;  receives  a  high  polish;  withstands  wear. 

REPRESENTATIVE  USES  OF  WOOD. 

Abroad,  the  wood  is  used  in  docks,  ships,  machine  parts,  piles,  trestles, 
bridges,  floors,  wagons,  carriage-shafts,  furniture,  and  belaying-pins. 
In  the  United  States,  it  is  occasionally  used  in  veneers,  automobile 
spokes,  turnery,  and  in  the  tips  of  fishing  rods. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

72  (Laslett). 
MODULUS  OF  ELASTICITY. 

1,090,000  (Laslett). 
MODULUS  OF  RUPTURE. 

10,000  (Thurston). 
REMARKS. 

The  Yellow,  Gray,  and  Black  varieties  recognized  by  dealers  come  from 

the  same  species,  the  distinctions  being  due  to  differences  in  the  ages 

and  environment  of  the  trees  from  which  the  several  kinds  were  cut. 

Black  Greenheart  resembles  Lignumvitse  and  is  valued  more  highly  than 

the  others.1 


^ee  also  "Greenheart,"  Mell  and  Brush  (United  States  Forest  Service, 
Circular  No.  211). 


202  ORGANIC  STRUCTURAL  MATERIALS 


PERSIMMON         EBONY         OSAGE  ORANGE         CHERRY 

Diospyros  Toxylon  Prunus 

The  Persimmon  (Diospyros  virginiana)  grows  in  the  eastern 
and  southern  parts  of  the  United  States  and  is  a  member  of  the 
Ebony  family  (Ebenacece).  The  trees  may  be  known  by  their 
fruit,  which  is  remarkably  astringent  when  green,  but  sweet  and 
palatable  when  ripe.  The  wood  is  tough  and  hard.  The  sap- 
wood,  which  resembles  fine-grained  hickory,  is  of  a  light  brown 
color,  while  the  thin  heartwood  is  almost  black.  Persim- 
mon wood  is  sometimes  used  for  plane-stocks,  shuttles,  and 
shoe-lasts. 

The  true  Ebony  (Diospyros  ebenwri)  grows  in  Ceylon,  India, 
and  Siam.  The  Mexican  Ebony  (Diospyros  ebenaster),  which  is 
a  native  of  India,  has  been  cultivated  in  the  tropics  of  the  western 
hemisphere,  and  in  the  Philippine  Islands.  The  Madagascar 
Ebony  (Diospyros  mespiliformis)  is  a  native  of  tropical  Africa, 
and  the  Green  Ebony  (Diospyros  chloroxylori)  is  a  native  of 
southern  India.  There  are  other  sources  in  this  and  other 
genera.  The  Ebony  of  commerce,  which  is  fine-grained,  very 
hard  and  heavy,  more  or  less  durable,  and  of  a  deep  black  color, 
is  used  for  veneers,  cabinet  work,  and  piano  keys. 

The  Osage  Orange  or  Bois  d'Arc  (Toxylon  pomiferwri)  grows 
naturally  in  parts  of  Oklahoma,  Arkansas,  Texas,  and  Louisiana, 
while  transplanted  trees  have  succeeded  as  far  north  as  New 
England.  The  more  or  less  slender  trees  yield  useless  fruit  which, 
in  size  and  general  appearance,  suggests  the  common  orange. 
The  thin  sapwood  is  of  a  light  yellow  color,  while  the  thick  heart- 
wood  is  bright  orange.  The  wood  is  very  hard  and  strong.  It 
takes  a  beautiful  polish  and  is  worthy  of  much  more  attention 
than  it  receives.  The  aborigines  made  bows  and  arrows  of  it, 
whence  the  name  Bois  d'Arc. 

The  Wild  Black  Cherry  (Prunus  serotina)  grows  in  many  localities  in 
the  eastern  half  of  the  United  States,  and  bears  small,  purplish-black 
cherries,  that  are  sweetly  bitter  when  ripe.  The  Cherry  wood  of  commerce 
is  obtained  from  this  species.  The  strong,  clean,  straight-grained,  hard, 
durable,  fine,  reddish  colored  wood  is  easily  worked;  it  receives  a  high 
polish,  and  is  used  in  cabinet  wood  and  indoor  finish.  It  is  often 
stained  so  as  to  imitate  mahogany,  while  it  itself  is  often  imitated  by 
staining  the  wood  of  the  Sweet  Birch  (Betula  lento).  Wild  Cherry  bark 
contains  a  bitter  principal  that  is  used  in  medicine. 


BROADLEAF  TRUNKS  AND  WOODS  203 

Persimmon.  Diospyros  virginiana  Linn. 

NOMENCLATURE  (Sudworth). 

Persimmon    (local  and   common         Simmon,  Possumwood  (Fla.). 

name).  Plaqueminier  (La.)- 

Date  Plum  (N.  J.,  Tenn.). 

LOCALITIES. 

Rhode  Island  to  Florida,  westward  intermittently  to  Missouri  and  Texas. 

FEATURES  OF  TREE. 

Occasionally  seventy  feet  in  height;  one  to  two  feet  in  diameter;  the  soft, 
plum-like  fruit  is  astringent  when  green  and  sweet  when  ripe. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  dark  brown  or  black;  sapwood  light  brown,  often  with  darker 
spots;  very  thin  heartwood;  very  close-grained;  compact  structure;  the 
medullary  rays  are  conspicuous;  resembles  Hickory. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Hard,  heavy,  and  strong. 

REPRESENTATIVE  USES  OF  WOOD. 

Plane-stocks,  shoe-lasts,  etc.;  prized  for  shuttles. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT 

49. 
MODULUS  OF  ELASTICITY. 

1,110,000. 
MODULUS  OF  RUPTURE. 

12,400. 

REMARKS. 

The  astringent  properties  of  the  unripe  fruit  are  due  to  tannic  acid. 
The  dark  heartwood  is  not  greatly  developed  in  trees  that  are  under 
one  hundred  years  old. 


204  ORGANIC  STRUCTURAL  MATERIALS 

I  Madura  aurantiaca  Nutt 

Osage  Orange.  { m      i  v          D  f 

[  Toxylon  pomiferum  Raj. 

NOMENCLATURE  (Sud worth). 

Osage  Orange  (local  and  common         Hedge,    Hedge-plant,    Osage    (111. 

name).  la.,  Neb.)- 

Bois  D'  Arc  (La.,  Tex.,  Mo.).  Mock  Orange  (La.). 

Bodark,  Bodock  (Kans.).  Bow-wood  (Ala.). 

Yellow-wood,  Osage  Apple  Tree 
(Tenn.). 

LOCALITIES. 

Southern  Arkansas,  Oklahoma,  and  Texas;  cultivated  elsewhere,  as  in 
Massachusetts,  Pennsylvania,  and  Michigan. 

FEATURES  OF  TREE. 

Twenty  to  fifty  feet  in  height;  rarely  beyond  one  and  one-half  feet  in 
diameter;  the  form  of  the  useless  fruit  suggests  that  of  the  orange.  The 
trees  survive  when  planted  close  together  and  the  living  trunks  of  trees 
thus  planted  are  often  used  as  fence  posts. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  bright  orange,  which  turns  brown  on  exposure;  the  sap  wood 
is  light  yellow;  close-grained;  the  annual  rings  are  clearly  marked. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  very  strong,  flexible,  and  durable  in  contact  with  the  soil; 
receives  a  beautiful  polish;  shrinks  in  seasoning. 

REPRESENTATIVE  USES  OF  WOOD. 

Fence-posts,  piles,  telegraph  poles,  railway  ties,  paving-blocks,  occasion- 
ally indoor  decoration,  wagon  felloes,  and  machinery. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

48. 
MODULUS  OF  ELASTICITY. 

1,300,000. 
MODULUS  OF  RUPTURE. 

16,000. 
REMARKS. 

The  Indians  used  this  wood  for  bows.  The  early  name,  Bois  D'Arc,  has 
been  corrupted  to  Bow  Dark  or  Bodark.  Bodark  wagon  felloes  are  much 
prized  in  arid  regions  where  the  rains  are  confined  to  a  short  season  of 
the  year,  and  where  the  balance  of  the  year  is  hot  and  dry.  Under 
such  circumstances,  wheels  made  of  some  other  woods  shed  their  tires 
and  are  otherwise  less  satisfactory. 


BROADLEAF  TRUNKS  AND  WOODS  205 

f  Prunus  serotina  Ehrh. 
Wild  Black  Cherry,  Wild  Cherry.  <  -n    -, 

\  Padus  serotina 

NOMENCLATURE  (Sudworth). 

Wild  Black  Cherry,  Wild  Cherry  Rum  Cherry  (N.  H.,  Mass.,  R.  I., 

(local  and  common  names).  Miss.,  Neb.). 

Black  Cherry  (Me.,  N.  H.,  Vt.,  Whiskey  Cherry    (Minn.). 

R.  I.,  N.  Y.,  Miss.,  Ky.,  Mich.,  Choke  Cherry  (Mo.,  Wis.,  la.). 
Wis.,  Ind.,  Neb.). 

LOCALITIES. 

Eastern  to  central  United  States. 

FEATURES  OF  TREE. 

Forty  to  eighty  feet  in  height;  two  to  three  or  more  feet  in  diameter;  the 
bark  and  pea-sized  fruit  contain  a  bitter  principal. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  reddish  brown;  sapwood  yellow;  fine,  straight  grain;  compact 
structure. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  hard,  strong,  and  easily  worked. 

REPRESENTATIVE  USES  OF  WOOD. 

Cabinet  work  and  interior  finish;  preferred  beyond  many  other  woods  as 
a  base  upon  which  enamelled  paints  are  to  be  applied. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

36. 
MODULUS  OF  ELASTICITY 

1,200,000. 
MODULUS  OF  RUPTURE. 

11,700. 
REMARKS. 


206  ORGANIC  STRUCTURAL  MATERIALS 

MAHOGANY 

Swietenia,  Khaya,  Soymida,  Cedrela,  etc. 

The  many  botanical  sources  of  the  woods  known  as  Mahogany, 
may  be  grouped  upon  a  geographical  basis  as  they  grow  in 
Central  America,  the  East  Indies  and  Africa. 

Central  American  Mahogany  was  originally  obtained  from  the 
Mahogany  (Swietenia  mahagoni),  but  is  now  derived  from  other  trees 
as  well,  such  as  some  of  those  of  the  genus  Cedrela.  Central  Ameri- 
can Mahogany  was  once  divided  as  it  came  from  the  then  Spanish 
American  possessions  and  from  Honduras.  The  first  was  called 
"Spanish  Mahogany"  and  the  last  "Honduras  Mahogany."  Most  of 
the  wood  that  comes  from  Mexico  is  named  from  the  ports  from 
which  it  is  shipped.  There  are  thus,  Frontera,  and  other  kinds  of 
Mahogany.  East  Indian  Mahogany  is  obtained,  largely,  from  the 
Mahogany  (Soymida  febrifuga).  The  African  sources  are  very 
numerous,  a  fact  that  explains  the  differences  that  exist  in  the  quali- 
ties of  these  woods.  The  most  'important  source  is  the  Mahogany 
(Khaya  senegalensis) ,  while  other  sources  are  the  species  Khaya 
grandifolia  and  Entandrophrdgma  candollei.  Some  Mahogany  is 
brought  from  the  Philippine  Islands. 

Mahogany  has  been  used  to  a  limited  extent  in  construction, 
but  is  now  so  greatly  valued  as  a  decorative  wood  that  it  is  used 
for  little  else,  save,  occasionally,  the  hulls  of  small  pleasure  craft. 
The  decorative  value  of  this  wood  is  due  to  a  combination  of 
appearance,  working  qualities,  and  durability.  The  appearance 
of  mahogany  is  influenced  by  its  cellular  structure  and  its  warm 
reddish  color.  The  latter  is  often  comparatively  light  at  first; 
but,  usually,  darkens  eventually  to  characteristic  tints,  which, 
however,  are  usually  induced  at  once  by  means  of  stains.  The 
cellular  structure  of  mahogany  is  not  only  beautiful  of  itself, 
but  is  such  as  to  respond  to  the  stains  and  finishing  processes 
commonly  applied.  Mahogany  works  and  glues  well.  It  is 
very  durable;  few  woods  shrink  or  distort  less  than  Mahogany 
after  it  is  in  place.  It  should  be  noted  that  woods  produced  in 
different  localities  differ  in  grain  and  color  from  one  another,  and 
that  pieces  cut  from  different  trees  in  the  same  locality  often 
differ  also.  Beautiful  grain  effects  are  often  seen  where  trunks 
and  branches  join,  and  such  pieces,  known  as  "crotches,"  usually 
bring  very  high  prices. 


BROADLEAF  TRUNKS  AND  WOODS  207 

The  Spanish  Cedar  (Cedrela  odorata)  is  not  a  true  Cedar.  In 
spite  of  its  name  it  is  not  even  remotely  related  to  the  trees  from 
which  the  Cedar  woods  of  commerce  are  ordinarily  obtained. 
The  true  Cedars  are  all  Conifers,  whereas  this  tree  is  a  Dicotyle- 
don, and  belongs  to  the  family  which  includes  the  mahoganies.2 
Aside  from  this  the  wood  suggests  fine  Cedar  in  appearance,  and 
possesses  the  odor  that  is  associated  with  that  wood.  It  is  used 
for  cigar  boxes  and  cabinet  work. 

The  Prima  vera  or  White  Mahogany  (Tabebuia  donnell- 
smithii)  is  related  to  the  Catalpas,  and  grows  in  Mexico  and 
Central  America,  where  it  is  often  associated  with  the  true 
Mahogany  (Swietenia  mahagoni).  The  wood  resembles  true 
Mahogany,  save  in  color,  which  is  a  light  yellow  that  darkens 
with  age.  The  characteristic  color  of  the  finished  wood  is  golden- 
yellow.  It  is  hard  to  find  large  pieces  of  Prima  vera  free  from 
worm  holes.  The  wood  is  used  in  car  finish,  cabinet  work,  and 
fine  furniture,  where  ordinary  Mahogany  might  be  used,  save 
for  its  darker  color. 


1  The  name  Mountain  Mahogany  is  applied  to  several  trees  that  grow  in 
the  Rocky  Mountain  region  and  yield  woods  that  are  sometimes  employed 
for  fuel.     Some  of  these  species  are  Mountain   Mahogany    (Cercocarpus 
ledifolius),    Mountain   Mahogany;   Valley   Mahogany    (Cercocarpus    parvi- 
folius),  Mountain  Mahogany;  Birchleaf  Mahogany  (Cercocarpus  parvifolius 
betuloides). 

2  Meliacese  has  been  divided  into  Swietenice,  which  includes  some  of  the 
true  Mahoganies,  and  Cedreloe,  which  includes  about  nine  genera  and  twenty- 
five  species,  distributed  over  tropical  Asia  and  America.     See  also  "True 
Mahogany,"  Mell  (United  States  Department  of  Agriculture  Bulletin  No. 
474,  1917). 


208  ORGANIC  STRUCTURAL  MATERIALS 

Mahogany.  Swietenia  mahagoni  Jacq. 

NOMENCLATURE. 

Mahogany    (local    and    common  Mexican  Mahogany  (Frontera,  and 

name).  other  Mexican  ports). 

Spanish   Mahogany    (Cuba,   San  Honduras  Mahogany  (Honduras). 

Domingo,  West  Indies).  Bay  wood,  Madeira,  Redwood. 

LOCALITIES. 

Florida  Keys,  the  Bahamas,  the  West  Indies,  Mexico,  Central  America, 
and  Peru. 

•  FEATURES  OF  TREE. 

Florida  specimens  are  forty-five  feet  in  height  and  two  or  more  feet  in 
diameter;  foreign  trees  are  larger. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

Heartwood  light,  rich  reddish  brown;  the  thin  sapwood  is  yellow;  smooth, 
fine,  uniform  texture;  inconspicuous  rings;  the  conspicuous  pores  are 
sometimes  filled  with  white  substance. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong  and  durable,  but  brittle;  it  holds  glue,  takes  stains,  and  receives  a 
high  polish;  it  changes  but  little  in  seasoning  and  stands  well. 

REPRESENTATIVE  USES  OF  WOOD. 

Veneers  and  cabinet-work;  was  formerly  used  in  ship-building. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

45. 
MODULUS  OF  ELASTICITY. 

1,510,000. 
MODULUS  OF  RUPTURE. 

14,000. 
REMARKS. 

The  desirability  of  Mahogany  from  this  and  other  species  varies  with 
locality.  Mahogany  is  usually  stained, 


BROADLEAF  TRUNKS  AND  WOODS  209 

Spanish  Cedar,  Mexican  Cedar.  Cedrela  odorata  Linn. 

NOMENCLATURE. 

Spanish  Cedar,  Mexican  Cedar,  Cuban  Cedar  (local  and  common  names). 

LOCALITIES. 

Mexico,  Cuba,  and  the  West  Indies. 

FEATURES  OF  TREE. 

Fifty  to  eighty  feet  in  height;  two  to  five  feet  in  diameter;  pale  yellow 
flowers ;  there  are  pods  that  suggest  pecan  nuts  as  to  form ;  the  form  of 
the  tree  suggests  that  of  the  English  Walnut  (Juglans  regia). 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  brownish  red;  straight,  even,  compact  grain. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  fragrant,  porous,  and  durable;  resembles  Cedar  woods  which  are 
derived  from  coniferous  trees,  and  also  resembles  Mahogany. 

REPRESENTATIVE  USES  OF  WOOD. 

Cigar-boxes,  boats,  and  sometimes  cabinet-work;  may  be  used  in  place  of 
Mahogany. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
MODULUS  OF  ELASTICITY. 
MODULUS  OF  RUPTURE. 


REMARKS. 

The  trees  grow  rapidly.  The  related  Australian  Red  Cedar  (Cedrela  aus- 
tralis)  is  locally  used  for  furniture,  joinery,  carriages,  ceilings,  and  door 
frames.  These  woods  must  not  be  confused  with  true  cedars,  which 
are  derived  from  non-related  trees  of  the  coniferous  series. 


The  Toon  Cedar  (Cedrela  toona  Roxburgh}  of  the  Orient  is  the  same  as  the 
Red  Cedar  (Cedrela  australis  F.  v.  M.}.  of  Australia.  The  Cedar  (Cedrela 
odorata  Blanco}  is  thought  to  be  a  distinct  Philippine  species. 


210  ORGANIC  STRUCTURAL  MATERIALS 

White  Mahogany.  Tabebuia  donnett-smithii  Rose 

Prima  vera. 

NOMENCLATURE. 

White    Mahogany,    Prima    vera         Jenicero, 
(local  and  common  names)  Genesero, 

Roble. 

LOCALITIES. 

Southern  States  of  Mexico  to  Peru. 

FEATURES  OF  TREE. 

Fifty  to  ninety  feet  in  height;  two  to  four  feet  in  diameter;  trunks  are  often 
clear  for  thirty  or  forty  feet  from  the  ground;  numerous  golden-yellow 
flowers  precede  the  leaves;  a  beautiful  tree. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

The  heartwood  is  of  a  cream  white  color  which  often  darkens  with  expo- 
sure; the  thin  sapwood  is  almost  white;  beautiful  mottled  or  clouded 
effects  usually  seen  best  when  pieces  are  quarter  sawn;  fine  grained; 
the  wood  resembles  mahogany  save  in  color. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Moderately  heavy,  tough,  rather  soft  and  not  strong;  dries  without  check- 
ing, works  well  and  stands  well;  receives  stains  and  retains  high  polish; 
durable  in  contact  with  the  soil. 

RFPRESENTATIVE  USES  OF  WOOD. 

Local  constructions  and  railway  ties;  widely  used  for  cabinet-work  and 
fine  furniture;  veneers. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

28.  (reported). 
MODULUS  OF  ELASTICITY. 


MODULUS  OF  RUPTURE. 


REMARKS. 

The  wood  can  be  used  where  fine,  light  colored,  cheerful  effects  are 
required;  or  it  can  be  stained  so  as  to  imitate  ordinary  mahogany. 
The  wood  of  the  butternut  or  white  walnut  is  sometimes  sold  as  white 
mahogany  but  is  seldom  if  ever  seriously  confused  with  the  true  wood.1 


aSee  also  Botanical  Gazette  (Vol.  XVII,   1892,  p.  418) ;  Contribution, 
United  States  National  Herbarium  (Vol.  I,  No.  9,  p.  346). 


BROADLEAF  TRUNKS  AND   WOODS  211 

TEAK 

Tectona,  Oldfieldia 

The  Indian  Teak  (Tectona  grandis)  grows  in  India,  Burmah, 
the  Malay  Peninsula,  Sumatra,  Java,  and  Ceylon,  and  is  a  very 
important  tree  that  is  sometimes  referred  to  as  the  "Oak  of  the 
East  Indian  forests."  The  less  plentiful  African  Teak  (Old- 
fieldia africana)  is  a  native  of  western  tropical  Africa.  These  two 
trees  are  not  related  to  one  another,  yet  they  yield  woods  that 
possess  the  same  anatomical  characteristics. 

Teak  wood  is  fairly  hard  and  heavy.  The  colors  of  freshly 
cut  pieces  vary  from  light  yellow  to  brownish  red.  Older  pieces 
are  much  darker.  Teak  contains  a  peculiar  resin  which  probably 
contributes  to  durability  for  which  this  wood  is  noted.  This 
resin  also  serves  because  it  is  obnoxious  to  insects  and  because  it 
preserves  iron  fastenings.  Teak  was  long  regarded  as  one  of  the 
best  of  all  woods  for  ship-building.  It  is  now  used  in  many 
local  constructions,  such  as  railway  ties,  bridge-timbers,  and 
artillery  wagons.  It  is  extensively  exported  to  Great  Britain. 
The  grain  is  such  that  the  wood  is  often  carved,  and  Teak  wood 
is  now  known  in  North  America  chiefly  through  such  carvings.1 


1  See  also  "Wood, "  Boulger  (London,  2d  Ed.,  p.  285.) 


212  ORGANIC  STRUCTURAL  MATERIALS 

Teak.  Tectona  grandis 

NOMENCLATURE. 

Teak.  Teek. 

Indian  Oak.  Sagwan. 

LOCALITIES. 

India,  Burma,  Siam,  and  Ceylon. 

FEATURES  OF  TREE 

Eighty  to  one  hundred  feet  in  height;  three  to  four  feet  in  diameter;  some- 
times larger;  a  straight  trunk;  large,  drooping,  deciduous  leaves. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  is  of  a  variable,  brownish-yellow  color;  a  straight,  even-grained 
wood. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Moderately  hard,  strong,  and  easily  worked;  stands  well;  oily,  fragrant, 
resists  termites,  and  preserves  iron. 

REPRESENTATIVE  USES  OF  WOOD. 

Furniture,  ship-building,  timbers,  and  backing  for  armor-plates. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
50  (Laslett). 

MODULUS  OF  ELASTICITY. 
1,338,000  (Laslett). 
2,100,000  (Thurston). 

MODULUS  OF  RUPTURE. 
15,000  (Thurston). 

REMARKS. 

It  is  thought  that  the  properties  by  which  iron  fastenings  are  preserved, 
and  by  which  termites  are  repelled,  are  due  to  oil  contained  in  the  wood. 
Burma  Teak,  Malabar  Teak,  and  other  kinds  take  their  names  from  the 
districts  in  which  they  were  produced,  or  from  which  they  were  shipped. 
Transplanted  specimens  have  not  succeeded  well  in  California.  The 
distinct  African  Teak  (Oldfieldia  africana)  yields  a  wood  that  is  some- 
times marketed  as  African  Mahogany  and  African  Oak. 


BROADLEAF  TRUNKS  AND  WOODS  213 

Some  other  tropical  species  that  yield  widely  known  woods, 
or  other  products,  or  that  are  valued  in  landscape  work,  are 
as  follows: 

Sabicu  (Lysiloma  sabicu). — This  West  Indian  wood  is  hard,  heavy, 
strong,  and  durable.  It  seasons  and  works  well  and  has  been  used  for 
ships  and  furniture.  The  wood  is  of  a  dark  chestnut-brown  color. 
Some  pieces  are  highly  figured.  The  appearance  and  the  working  quali- 
ties of  the  wood  are  such  that  it  may  be  used  in  place  of  rosewood. 

Sissoo  (Dalbergia  sissoo) . — These  trees  grow  in  northern  India.  Some 
transplanted  specimens  have  succeeded  in  other  places  as  California. 
The  wood,  which  is  highly  valued  in  India,  is  hard,  heavy,  strong,  and 
elastic.  The  sapwood  rots  quickly,  but  the  heartwood  remains  sound 
and  hardens  as  the  wood  grows  older.  Sissoo  seasons  well  and  stands 
well.  It  is  used  in  wheels,  boat-building,  agricultural  implements,  and 
furniture.  Gun-carriage  wheels  made  of  Sissoo  wood  are  highly  prized. 
Some  pieces  of  Sissoo  are  almost  as  beautiful  as  pieces  of  rosewood.  An 
important  source  of  commercial  rosewood  is  related  to  the  Sissoo. 

The  Rubber  Tree. — The  substance  known  as  India  rubber  is  like  sugar 
in  that  its  constituents  exist  in  a  number  of  unrelated  plants.  These 
constituents  form  part  of  a  milky  juice  which  is  secreted  by  most  of 
the  plants  in  question,  and  which  is  known  as  latex.  Latex,  which 
is  quite  distinct  from  sap,  is  a  thin,  watery  emulsion  made  up  of  cream- 
like  globules  suspended  in  a  thinner  liquid  of  different  composition;  the 
appearance  of  latex  is  similar  to  that  of  cows'  milk.  The  latex  of  the 
common  milkweed  is  a  familiar  example.  An  exception  to  the  rule  that 
rubber  is  obtained  from  latex  is  furnished  by  the  Guayule  plant.  The 
rubber  obtained  from  this  plant  is  distinct  from  most  others  in  that  it  is 
not  obtained  from  latex  but  exists  as  such  in  the  cells  of  the  plants. 

The  trees,  vines,  and  shrubs  from  which  India  rubber  may  be  obtained 
are  numbered  by  the  hundred,  but  the  sources  from  which  it  is  actually 
obtained  in  commercial  quantities  are  comparatively  few.  The  prin- 
cipal trees  from  which  it  is  obtained  are  the  Para  or  Hevea  Rubber  Tree 
(Hevea  braziliensis)  the  Central  American  Rubber  Trees  (Castilla 
elastica  and  others)  and  the  Assam  Rubber  Tree  (Ficus  elastica).  The 
wood  of  the  rubber  tree  is  seldom  employed  save  locally.  It  should  be 
noted  that  the  latex  from  which  India  rubber  is  obtained  is  secreted  only 
under  favorable  conditions.  (See  also  Chapter  XVII). 

The  Pepper,  California  Pepper  or  Peruvian  Mastic  (Schinus  molle) 
was  introduced  into  California  from  Peru  by  the  early  Spanish  mission- 
aries, and  is  now  one  of  the  most  popular  shade  trees  on  the  Pacific 
Coast,  south  of  San  Francisco.  The  Pepper  tree  grows  to  heights  of 
thirty  to  fifty  feet.  The  outline  suggests  that  of  the  Apple  tree,  while 
the  drooping  foliage  suggests  the  foliage  of  the  Willow.  There  are  long 
sprays  of  rose-tinted  berries,  masses  of  slender,  drooping  branchlets, 
and  delicate,  bright  evergreen  leaves  that  emit  a  pleasant,  pungent 


214  ORGANIC  STRUCTURAL  MATERIALS 

odor.  The  berries  are  the  size  of  currants  or  pepper  corns,  whence  the 
name  Pepper  tree.  The  soft,  smooth,  whitish-colored  woods  are  seldom 
employed,  save  for  fuel.  The  California  Pepper  tree  is  the  host  of  the 
"black  scale,"  and  is  now  being  replaced  by  the  better,  faster-growing, 
Longleaved  Pepper  tree  (Schinus  terebinthifolius)  from  Brazil. 

The  Tung  Oil  Tree.— The  Tung  Oil  tree  (Aleurites  fordii) ,  also  known 
as  the  Chinese  Wood  Oil  tree,  belongs  to  the  family  Euphorbiaceae.  It 
is  associated  with  China,  but  is  grown  in  other  parts  of  the  world,  and 
has  succeeded,  in  the  United  States,  in  southern  California,  and  in  the 
region  that  extends  southward  from  Cairo,  Georgia.  It  grows  to  a 
height  of  thirty  or  more  feet  and  has  an  ornamental  value  about  equal 
to  that  of  the  Cat&lpa.  The  flowers  precede  the  leaves  and  cause  the 
tree  to  be  very  beautiful  when  in  bloom.  The  soft  wood  is  not  valuable; 
but  the  fruit,  which  suggests  an  apple  two  or  three  inches  in  diameter, 
contains  from  two  to  eight  large  seeds  from  which  the  Tung  oil  of  com- 
merce is  obtained.  The  tree  begins  to  bear  fruit  when  four  or  five  years 
old.  It  is  said  that,  in  China,  a  tree  yields  from  thirty  to  seventy-five 
pounds  of  seed  every  year.1 

The  Balsa  (Ochroma  lagopus). — This  native  of  Central  America  and 
the  West  Indies  attains  a  diameter  of  about  one  foot.  The  large,  broad 
leaves  resemble  those  of  the  Catalpa.  The  weak,  uniform,  spongy,  par- 
enchymatous  wood  is  free  from  knots  and  checks  and  is  so  soft  that  it 
can  be  indented  with  the  finger  nail.  It  is  one  of  the  lightest  of  all 
woods,  its  weight  of  seven  pounds  per  cubic  foot  being  half  that  of 
ordinary  cork.  It  does  not  last  well;  and  it  absorbs  water  so  readily 
that  it  soon  becomes  water  logged  unless  impregnated  with  paraffin  or 
some  similar  compound.  It  is  extremely  porous,  and  for  this  reason 
is  an  excellent  insulator  against  heat  and  cold.  Balsa  wood  is  used  in 
refrigerator  linings,  and,  after  treatment  with  paraffin,  is  used  in  life 
preservers  in  place  of  cork.  It  is  used  locally  for  canoes.2 

The  China  or  China-berry  (Melia  azedarach)  is  a  native  of  India, 
China,  and  some  other  parts  of  the  eastern  hemisphere,  but  is  now  grown 
successfully  in  many  parts  of  the  world,  including  districts  in  the  south- 
ern part  of  the  United  States.  The  China  tree  is  also  referred  to  as  the 
Pride  of  India,  the  Bead  tree,  and  the  Umbrella  tree.  The  short, 
straight  trunk  merges  abruptly  into  numerous  branches  that  radiate 
outward  like  the  ribs  of  an  umbrella.  The  peculiar  form,  rapid  develop- 
ment, and  thick,  handsome  foliage  cause  the  true  to  be  valued  in  land- 
scape effects,  wherever  it  will  grow.  The  wood,  which  is  sometimes 
improperly  referred  to  as  "White  Cedar"  and  "Bastard  Cedar,"  is  oc- 
casionally made  into  furniture.  The  berries  contain  pits  that  are  some- 
times used  as  beads. 

The  Rosewood. — There  are  many  "Rosewood  trees."  The  African 
Rosewood  (Pterocarpus  erinaceus)  grows  in  tropical  western  Africa.  The 
Brazilian  Rosewood  (probably  Dalbergia  nigra)  is  a  native  of  Brazil. 
The  Canary  Rosewood  (Convolvulus  scoparius)  grows  in  the  Canary 


BROADLEAF  TRUNKS  AND  WOODS  215 

Islands.  In  California,  rosewood  is  derived  from  the  stems  of  very 
large  rose  bushes.  Commercial  rosewood  is  hard,  tough,  fine  grained, 
and  compact.  The  colors  vary  from  rich  reds  to  chestnut  browns; 
there  are  often  black  streaks  and  sometimes  purplish  effects.  The  name 
Rosewood  is  due  to  the  more  or  less  pronounced  scent  of  roses  which  the 
woods  emit.  The  wood  is  also  known  by  other  names,  as  Blackwood 
and  Bloodwood.  Rosewood  is  sometimes  used  in  local  constructions, 
but  is  normally  seen  in  costly  furniture,  piano  cases,  burial  caskets,  and 
panel  work.  It  is  sometimes  associated  with  Circassian  Walnut  and 
Satinwood  in  the  decorative  work  in  compartment  cars.  An  oil,  dis- 
tilled from  one  of  the  species  from  which  commercial  rosewood  is  ob- 
tained, has  been  used  to  adulterate  attar  of  roses. 

The  Sandalwood. — The  Sandalwood  of  commerce  is  obtained  from 
many  botanical  sources.  The  genus  Santalum  alone  includes  about 
twenty  species.  Until  the  eighteenth  century,  Sandalwood  was  ob- 
tained from  China.  The  discovery  of  sources  on  the  Islands  of  the 
Pacific  led  to  lawless  traffic  and  much  bloodshed.  The  adventures 
associated  with  the  collection  of  this  wood  were  equal  to  those  encoun- 
tered in  whaling  and  the  search  for  ivory.  The  Sandalwood  tree  (San- 
talum album)  yields  a  reddish-brown,  close-grained,  very  fragrant  wood 
that  weighs  about  fifty-five  pounds  a  cubic  foot.  Red  Sandalwood  or 
Sanderswood  (Pterocarpus  santalinus)  yields  a  red  dye  that  is  known  as 
"santalin."  Sandalwood  was  prized  by  the  French  nobility  for  medal- 
lions that  were  mounted  on  otherwise  decorated  surfaces.  It  was  also 
sometimes  made  into  rich  furniture,  and  is  now  occasionally  seen  in 
finely  carved  small  objects,  as  jewel  boxes  and  fan  handles.  The 
powdered  wood  is  burned  as  incense.  A  fragrant  oil  is  separated  by 
distillation. 

Satinwood. — The  East  Indian  Satinwood  (Chloroxylon  swietenia),  grows 
in  India  and  Ceylon,  while  the  Yellow-wood  or  Satinwood  (Xanthoxylum 
cribrosum)  is  a  native  of  Florida  and  the  West  Indies.  There  are  other 
botanical  sources.  The  yellow  or  orange-colored  woods  are  hard,  heavy, 
close-grained,  durable,  and  beautifully  figured.  Pieces  from  San  Domingo 
and  Jamaica  are  particularly  beautiful  and  bring  the  highest  prices. 
Satinwood  is  very  valuable  and  is  seldom  used,  save  in  the  finest  cabinet 
work  and  furniture. 

A  valuable  list  has  been  prepared  by  Mell  under  the  title  "  Cabinet 
Woods  of  the  Future."3 

1  "The  China  Wood  Oil  Tree,"  Fairchild  (United  States  Bureau  of  Plant 
Industry,  Circular  No.  108);  Files  of  "Oil,  Paint  and DrugReporter;"  etc. 

2  Missouri  Botanical  Garden  Bulletin  (August,  1915,  p.  107);  The  Prop- 
erties of  Balsa  wood,"  Carpenter    (Proceedings,   American  Society   Civil 
Engineers,  May,  1916). 

3  "Cabinet  Woods  of  the  Future,"  Mell  (American  Forestry,  Vol.  XVI, 
No.  12. 


216  ORGANIC  STRUCTURAL  MATERIALS 

EUCALYPTUS 

Eucalyptus 

The  Eucalypts,  locally  known  as  Stringybarks,  Ironbarks, 
Mahoganies,  Box  and  Gum  trees,  are  natives  of  Australia  and  the 
neighboring  islands.1  The  genus  is  now  represented  by  culti- 
vated specimens  on  each  of  the  continents,  where,  in  some  places, 
it  has  influenced  topographical  and  other  conditions  to  a  remark- 
able degree2.  The  Riviera,  the  Campania,  the  Nilgheri  Hills 
in  southern  India  and  parts  of  Algeria,  Brazil,  and  California 
have  been  practically  transformed  by  Eucalyptus  trees. 

Eucalyptus  trees  are  noted  for  their  rapid  growth,  fine  appear- 
ance, great  size,  tough  and  durable  woods,  and  their  influence 
upon  sanitation. 

Rapid  Growth. — This  is  shown  by  specimens  of  the  Blue  Gum  (Euca- 
lyptus globulus)  that  have  lengthened  more  than  two  feet  in  a  single 
month.  In  three  years,  a  tree  of  this  species  attained  a  diameter  of 
about  nine  inches.  A  Pasadena  tree  was  five  feet  thick  at  the  end  of 
twenty-five  years,  while  some  specimens  in  Santa  Barbara  that  were 
twenty-five  years  old  compared  in  general  development  with  oaks  that 
were  over  two  hundred  years  old. 

Appearance. — The  trees  of  some  species  are  very  attractive  in  form. 
Some  of  the  trees  blossom  during  droughts  when  other  flowers  are  scarce; 
others  blossom  twice  a  year;  and  still  others  blossom  all  the  time. 

Size. — The  enormous  size  is  seen  in  specimens  of  the  Peppermint  tree 
(Eucalyptus  amygdalina}  that  have  grown  to  heights  of  over  four  hun- 
dred feet  and  are  the  tallest,  although  not  the  largest,  trees  known  to  man. 

Character  of  Woods. — Eucalyptus  woods  are  tough  and  hard  to  season 
but  some  of  them  are  very  valuable.  The  working  qualities  of  Aus- 
tralian grown  Jarrah,  Karri,  Tuart,  and  Red  Gum  woods  (Eucalyptus 
marginata,  Eucalyptus  diversicolor,  Eucalyptus  gomphocephala,  and  Euca- 
lyptus rostrata)  are  such  that  these  woods  are  highly  prized  in  many 
localities.  In  London  and  in  Paris,  blocks  of  Jarrah  and  Karri  woods 
have  been  used  to  pave  streets  subjected  to  heavy  traffic. 

REFERENCES. — Works  of  von  Mueller;  Report  J.  Ednie  Brown,  Forest 
Commissioner  of  Western  Australia;  Works  of  Abbot  Kinney  (Press  Baum- 
gardt,  Los  Angeles);  Ingham  (California  State  Agricultural  Experiment 
Station,  Bulletin  No.  196);  "Eucalypts  Cultivated  in  the  United  States," 
McClatchie  (United  States  Bureau  of  Forestry,  Bulletin  No.  35,  1902); 
' 'Utilization  of  California  Eucalypts, "Betts and  Smith  (United  States  Forest 
Service,  Circular  No.  179);  "Eucalypts  in  Florida,"  Zon  and  Briscoe  (United 
States  Forest  Service,  Bulletin  No.  87,  1911);  "Yield  and  Returns  of  Blue 
Gum  in  California,"  Woodbury  (United  States  Forest  Service,  Circular 
No.  210);  "Eucalypts,"  Pinchot  (United  States  Forest  Service,  Circular 
No.  59  Revised,  1907). 


BROADLEAF  TRUNKS  AND  WOODS  217 

Influence  upon  Health. — Improvement  in  the  health  of  residents  has 
followed  the  introduction  of  the  Blue  Gum  (Eucalyptus  globulus}  in 
malarial  districts  such  as  some  in  the  vicinity  of  Rome.  It  is  possible 
that  these  fortunate  results  may  have  been  influenced  to  a  slight  extent 
by  medicinal  compounds  in  the  foliage,  but  it  is  much  more  probable 
that  they  were  due  to  the  fact  that  the  leaves  of  this  species  evaporate 
large  quantities  of  water,  and  thus  reduce  the  moisture  conditions  neces- 
sary for  the  growth  of  mosquitoes. 

The  genus  may  be  summarized  from  the  viewpoint  of  the  living 
tree  and  from  the  viewpoint  of  the  woods  as  follows : 

Eucalyptus  Trees  Grow  Rapidly. — Some  of  them  grow  where  those  of 
other  species  will  not;  some  form  windbreaks  and  forest  cover;  some 
serve  in  landscape  effects;  some  afford  honey  and  many  yield  oils. 
The  hard,  tough  woods  present  an  unusual  range  of  possibilities.  Mc- 
Clatchie  enumerates  twenty-five  ways  in  which  these  woods  have  been 
used  in  Australia :  six  species  are  valued  for  bridge  timbers,  five  for  piles, 
nine  for  paving,  eight  for  posts,  three  for  railway  ties,  four  for  car  build- 
ing, five  for  lumber  and  shingles,  seven  for  carriage  parts,  two  for  cooper- 
age, and  two  for  handles.  Thus  far,  comparatively  little  eucalyptus 
lumber  has  been  produced  in  this  country,  but  experience  is  sufficient 
to  show  that  some  kinds  of  eucalyptus  can  be  used  in  place  of  other 
woods  that  are  now  used  in  the  United  States  for  piles,  posts,  poles, 
crossties,  mine  timbers,  paving  blocks,  insulator  pins,  furniture,  finish, 
veneers,  cooperage,  vehicle  stock,  and  tool  handles.  Eucalyptus  woods 
are  hard  to  season.  The  structure  is  complicated  and  the  woods  are 
full  of  water.  This  is  particularly  true  of  woods  produced  in  the  United 
States  where  the  trees  are  yet  comparatively  young.  No  really  sat- 
isfactory method  of  seasoning  the  woods  of  the  species  thus  far  intro- 
duced into  North  America  has  yet  been  worked  out  on  .a  commercial 
basis.  The  colors  of  the  woods  vary;  shades  of  yellow,  brown  and 
red  predominate. 

The  evergreen  leaves  exhibit  many  tints,  normally  of  the  colors 
gray,  blue,  and  green.  The  characteristic  odor  is  the  only  point  in 
common  between  the  leaves  of  young  and  old  trees  of  some  species. 
The  genus  includes  nearly  two  hundred  and  fifty  species. 

1  The  nomenclature  is  confusing.     There  are  eleven  Stringybarks,  eight 
Ironbarks,   nine   Red   Gums,    and   twelve   Blue   Gums.     The   Blue   Gum 
(Eucalyptus  globulus)  is  the  species  commonly  referred  to  when  the  Eucalyp- 
tus is  mentioned  in  North  America. 

2  Eucalyptus  trees  do  not  grow  well  in  the  United  States  outside  of  Cali- 
fornia, Arizona,  New  Mexico,  Texas,  and  Florida  and  their  success  in  New 
Mexico,  Texas,  and  Florida  has  not  been  remarkable.     The  Florida  climate 
is  favorable  most  but  not  all  of  the  time.     The  climate  of  Southern  Cali- 
fornia is  more  equable  and  this  district  must  still  be  regarded  as  the  only 
real  North  American  locality. 


218  ORGANIC  STRUCTURAL  MATERIALS 

Blue  Gum,  Fever  Tree.  Eucalyptus  globulus 

NOMENCLATURE. 

Blue  Gum  (local  and  common  name).     Fever  Tree,  Balluck  (Australia). 

LOCALITIES. 

Native  of  Australia;  acclimated  in  southern  California  and  elsewhere  in 
frostless  regions  throughout  the  world. 

FEATURES  OF  TREE. 

Sometimes  three  hundred  or  more  feet  in  height;  three  to  six  feet  in  di- 
ameter; bark  varies  with  age  and  environment;  the  form  and  color  of  the 
leaves  which  are  sometimes  twelve  inches  in  length,  vary  with  age; 
characteristic  odor/ 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  straw  color;  sap  wood  lighter;  complicated  cellular  arrange- 
ment; indistinct  annual  rings. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard  and  heavy;  the  cellular  structure  is  such  that  the  wood  is  hard  to 
split  and  work  after  it  has  been  seasoned ;  the  American  product  is  hard 
to  season,  possibly  because  the  trees  are  comparatively  young  and  full 
of  water.  Not  durable  in  contact  with  the  soil. 

REPRESENTATIVE  USES  OF  WOOD. 

Principal  experience  is  abroad,  where  foreign-grown  pieces  are  used  for 
rollers,  paving-blocks,  ship-building,  carriage  parts,  and  fuel.  In  the 
United  States,  pieces  boiled  in  water,  and  then  in  linseed  oil,  are  used 
for  insulator  pins  on  telegraph  poles;  in  California,  the  wood  is  used  for 
piles  and  mine-timbers;  an  important  fuel  in  southern  California. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
43  to  69  (Mueller).         57  to  69  (Laslett).        47.9  (Betts  &  Smith).1 

MODULUS  OF  ELASTICITY. 

1,712,000  (Average  of  17  tests  of  California-grown  specimens).1 

MODULUS  OF  RUPTURE. 

12,400  (Average  of  17  tests  of  California-grown  specimens).1 

REMARKS. 

It  should  be  noted  that  the  name  Blue  Gum  is  applied  to  at  least  eleven 
other  species.  This  Blue  Gum  is  the  Eucalyptus  of  California. 


1  United  States  Forest  Service,  Circular  No.  179,  p.  12. 


BROADLEAF  TRUNKS  AND  WOODS  219 

Red  Gum.  Eucalyptus  rostrata 

NOMENCLATURE. 

Red  Gum  (local  and  common  name). 

LOCALITIES. 

Australia.     Acclimated  in  California  and  elsewhere. 

FEATURES  OF  TREE. 

One  hundred  or  more  feet  in  height;  the  tress  are  often  crooked;  the  bark, 
when  young,  is  red. 

COLOR,  APPEARANCE,  OR  GRAIN  OP  WOOD. 

The  color  of  the  heartwood  varies  from  light  red  to  dark  blood-red; 
the  color  darkens  with  age;  close-grained;  the  cellular  arrangement  is 
complicated. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong,  hard,  and  heavy;  said  to  resist  attacks  of  shipworms  and  termites; 
pieces  cut  from  American  trees  are  hard  to  season ;  capable  of  receiving  a 
high  polish. 

REPRESENTATIVE  USES  OF  WOOD. 

Principal  experience  is  abroad,  where  foreign-grown  pieces  are  Used  for 
posts,  bridge-timbers,  short  beams,  ship-timbers,  ties,  and  paving- 
blocks. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
55.6.1 

MODULUS  OF  ELASTICITY. 

1,201,000  (Average  of  9  tests  on  California-grown  specimens).2 

MODULUS  OF  RUPTURE. 

12,369  (Average  of  9  tests  on  California-grown  specimens).2 

REMARKS. 

A  Commission  on  State  Forests  and  Timber  Reserves  in  Melbourne  gave 
as  its  opinion  that  Red  Gum  is  the  "most  important  tree  in  the  State,  on 
account  of  its  durability  and  the  many  uses  to  which  it  (the  wood) 
is  put."  Von  Mueller  wrote  of  Red  Gum  as  "perhaps  the  most  im- 
portant of  the  entire  genus."  The  best  grade  of  lumber  is  obtained 
from  trees  over  one  hundred  years  of  age.  It  is  believed  that  Red 
Gum  trees  will  succeed  well  in  California,  but  the  wood  thus  far  pro- 
duced in  that  region  is  hard  to  season,  possibly  because  the  trees  are 
comparatively  young  and  full  of  water. 

1  United  States  Forest  Service,  Circular  No.  179,  p.  28. 

2  United  States  Forest  Service,  Circular  No.  179,  p.  16  and  28. 


220  ORGANIC  STRUCTURAL  MATERIALS 

Jarrah.  Eucalyptus  marginata 

NOMENCLATURE. 

Jarrah  (local  and  common  name). 
Mahogany  Gum  (Australia). 

LOCALITIES. 

Western  coast  of  Australia;  some  specimens  acclimated  in  California. 

FEATURES  OF  TREE. 

Ninety  to  one  hundred  or  more  feet  in  height;  two  to  five  feet  in  diameter; 
branches  concentrated  at  tops  of  trees. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

The  reddish-brown  wood  resembles  Mahogany;  it  also  resembles  Kauri 
wood. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Heavy,  somewhat  oily,  -non-absorbent,  does  not  take  fire  easily,  durable 
in  contact  with  the  soil;  it  may  be  polished;  it  wears  thin  evenly,  and  is 
said  to  repel  marine  and  land  wood-borers. 

REPRESENTATIVE  USES  OF  WOOD. 

Ship-building,  dock  and  bridge-timbers,  paving-blocks. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
65  (Ednie-Brown).1 

MODULUS  OF  ELASTICITY. 
2,080,000  (Ednie-Brown).1 

MODULUS  OF  RUPTURE. 
8,900  (Ednie-Brown).1 

REMARKS. 

The  principal  timber  tree  of  southwestern  Australia.  The  wood  is  often 
confused  with  that  of  the  Karri,  von  Mueller  calls  it  the  least  inflam- 
mable of  woods. 


1  Report  on  Forests  of  Western  Australia,  Presented  to  Parliament,  1896. 


BROADLEAF  TRUNKS  AND  WOODS  221 

Karri.  Eucalyptus  diversicolor 

NOMENCLATURE. 

Karri  (many  localities).  White  Gum  (Australia). 

LOCALITIES. 

Australia  and  New  Zealand;  some  specimens  acclimated  in  California. 

FEATURES  OF  TREE. 

Sometimes  three  hundred  and  fifty  feet  in  height;  from  four  to  eighteen 
feet  in  diameter;  a  straight,  graceful  tree,  the  lower  branches  of  which 
are  often  one  hundred  and  fifty  feet  from  the  ground;  smooth,  yellow- 
white  bark. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Heartwood  is  reddish-brown;  complicated  cellular  arrangement. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Hard,  heavy,  tough,  elastic,  non-absorbent,  and  durable;  difficult  to  work; 
wears  evenly;  possesses  a  characteristic  odor. 

REPRESENTATIVE  USES  OF  WOOD. 

Heavy  timbers,  railway  ties,  piles,  marine  work,  paving-blocks,  masts, 
and  lumber. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

63  (Ednie-Brown).1 
MODULUS  OF  ELASTICITY. 

2,890,000  (Ednie-Brown).1 
MODULUS  OF  RUPTURE. 

8,000  (Ednie-Brown).1 
REMARKS. 

The  name  diversicolor  is  due  to  the  fact  that  the  upper  and  lower  sides  of 
the  leaves  differ  in  color  from  one  another.  It  should  be  noted,  how- 
ever, that  this  characteristic  is  not  confined  to  this  particular  species  of 
this  one  genus.  The  Karri  was  once  named  Eucalyptus  colossea  because 
of  its  great  size.  This  Karri  is  quite  distinct  from  the  Kauri  (Dammara 
australis). 


Report  on  Forests  of  Western  Australia,  Presented  to  Parliament,  1896. 


222  ORGANIC  STRUCTURAL  MATERIALS 

Tuart.  Eucalyptus  gomphocephala 

NOMENCLATURE. 

Tuart  (local  and  common  name).         Tooart  (Australia). 
Tewart  (Australia).  White  Gum  (Australia). 

LOCALITIES. 

Australia;  acclimated  elsewhere. 

FEATURES  OF  TREE. 

Sometimes  one  hundred  and  fifty  feet  in  height;  four  to  six  feet  in  di- 
ameter; a  straight  trunk,  with  grayish-white  bark;  bright,  cheerful 
appearance. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

The  heartwood  is  of  a  light-yellow  color;  close-grained;  the  cellular 
arrangement  is  complicated. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Strong,  tough,  rigid,  hard,  heavy,  and  durable;  seasons  well;  is  hard  to 
split  and  work. 

REPRESENTATIVE  USES  OF  WOOD. 

Keele,  buffers,  stern-posts,  frames,  wheel-hubs,  and  shafts. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

67  (Ednie-Brown).1 
MODULUS  OF  ELASTICITY. 

2,300,000  (Ednie-Brown).1 
MODULUS  OF  RUPTURE. 

9,300  (Ednie-Brown).1 
REMARKS. 

In  California,  trees  have  reached  heights  of  eighty  feet  within  twenty-four 
years.  The  wood  is  one  of  the  strongest  of  all  those  used  in  construc- 
tion. 


Report  on  Forests  of  Western  Australia,  Presented  to  Parliament,  1896. 


BROADLEAF  TRUNKS  AND  WOODS  223 

Other  important  Eucalypts  are  as  follows: 

Sugar  Gum  (Eucalyptus  corynocalyx) . — This  is  one  of  the  Eucalypts 
that  has  succeeded  in  California.  The  tall,  erect  trees  resist  drought, 
but  are  less  able  than  Red  Gum  trees  to  withstand  frost.  The  trees 
blossom  profusely  for  several  months.  The  hard  wood  is  of  a  yellowish- 
white  color. 

Giant  Eucalypt  or  Peppermint  Tree  (Eucalyptus  amygdalind) . — This  is 
the  tallest,  although  not  the  largest,  of  trees  known  to  man.  The  leaves 
possess  an  odor  that  resembles  that  of  peppermint.  The  woods  are  less 
desirable  than  those  obtained  from  other  Eucalypts. 

Manna  Gum  (Eucalyptus  viminalis). — The  usually  erect  trees  resist 
comparatively  low  temperatures  almost  as  well  as  Red  Gum  trees. 
They  grow  rapidly,  are  thrifty,  and  yield  woods  that  vary  in  color  from 
light  brown  to  yellowish- white. 

Ironbark  or  Stringybark  (Eucalyptus  macrorrhyncha) . — The  durable, 
dark  gray,  fibrous  bark  is  used  locally  for  roofing,  while  fibers  drawn 
from  the  bark  are  used  in  making  string.  The  hard,  durable  wood  is 
employed  for  lumber,  shingles,  and  fuel. 

Red  Mahogany  or  Red  Gum  (Eucalyptus  resinifera) . — This  tree  yields 
a  hard,  heavy,  durable,  rich  red  wood,  the  appearance  of  which  suggests 
Mahogany.  The  wood  is  used  for  shingles,  posts,  piles,  and  paving- 
blocks,  and  is  suitable  for  use  in  furniture. 


CHAPTER  VIII 

NON-BANDED  TRUNKS  AND  WOODS 
Monocotyledons 

The  trunks  from  which  non-banded  woods  are  obtained  grow 
in  thickness  from  the  inside.  With  several  exceptions  these 
trunks  increase  principally  by  the  expansion  of  cells  already 
formed.1  There  are  no  layers  or  concentric  bands,  such  as 
characterize  the  woods  of  the  other  group.  On  the  contrary, 
the  wood-elements  are  distributed  in  such  a  way  as  to  appear 
as  dots  over  the  cross-sections.  The  trunks  normally  attain 
maximum  diameters  quite  early,  and,  unlike  Banded  trunks,  do 
not  continue  to  increase  throughout  their  lives.  The  trunks  are 
enclosed  by  integuments  that  bear  but  slight  resemblance  to 
bark.  The  few  forms  that  yield  structural  woods  are  asso- 
ciated with  the  tropics.  Of  these,  the  Palms  and  Bamboos  are 
examples. 

The  classes  of  wood-elements  that  exist  in  Non-banded  woods 
are  the  same  as  those  that  exist  in  Banded  woods.  Some  classes 
of  cells  may  be  modified  as  they  exist  in  certain  groups  of  Mono- 
cotyledons, just  as  they  are  also  modified  in  some  groups  of 
Dicotyledons  and  Conifers;  but,  as  far  as  known,  there  are  no 
cell  forms  that  are  peculiar  to  Non-banded  woods  alone.  The 
hardest  parts  of  Non-banded  stems  are  at  their  surfaces,  while 
the  softest  parts  are  at  their  centers.  In  many  cases,  as  with 
Bamboos,  the  tissues  at  the  center  are  quite  lacking. 

The  quantity  of  structural  material  obtained  from  the  Mono- 
cotyledons is  comparatively  small.  Yet  the  group  as  a  whole, 
with  some  forty  families,  including  numerous  genera  and  about 
twenty  thousand  species,  is  highly  important.  The  grasses, 
including  corn,  wheat,  rye,  sugar-cane  and  bamboo;  and  the 
Palms,  including  many  valuable  trees,  are  of  this  group. 


1  The  Yucca  and  the  Dragon-tree  are  Monocots  which  grow  by  a  cambium 
region  just  within  the  cortical  region. 

224 


NON-BANDED  TRUNKS  AND  WOODS  225 

PALM 

Palmacece 

More  than  one  thousand  species  of  Palms,  grouped  in  the 
family  Palmacese,  are  distributed  over  the  tropical  and  semi- 
tropical  regions  of  the  eastern  and  western  hemispheres.  The 
Washington  Palm  (Washingtonia  filif era),  and  several  Palmettoes 
(Sabal  palmetto,  Thrinax  parviflora,  etc.),  yield  woods  that  are 
used  in  the  United  States;  but  the  rule  is,  that  the  trees,  rather 
than  the  woods,  are  valued  in  this  country.1 

The  wood  is  soft,  light,  weak,  non-coherent,  and  more  or  less 
porous.  Large  fiber-bundles  contrast  sharply  with  the  surround- 
ing tissue,  and  cause  sections  to  present  a  spotted  appearance  (see 
preceding  figure  2).  Palm  wood  is  comparatively  safe  from 
the  attacks  of  shipworms,  which  are  not  "  worms"  but  mollusks. 
These  mollusks  line  the  surfaces  of  their  tunnels  with  shell,  for 
which  the  weak  and  porous  wood  is,  apparently,  an  insufficient 
foundation. 

The  long  leaf-stalks  of  the  Washington  Palm  are  worthy  of 
attention.  The  material  of  which  these  stalks  are  composed 
resembles  that  of  which  Bamboo  is  composed.  The  stalks  are 
seldom  used,  although  they  present  what  is,  weight  for  weight, 
one  of  the  strongest  of  all  materials. 

Two  roughly  cured  stalks  were  tested.  The  central  portions  of  each 
specimen  broke,  leaving  the  edges,  which  stripped,  without  signs  of 
fracture.  In  one  case  the  Modulus  of  Rupture  was  11,370  and  in  the 
other  case  it  was  10,150.  The  figures  were  averaged  for  the  entire  sec- 
tions, including  the  parts  that  stripped  without  breaking.  The  strength, 
which  would  doubtless  be  increased  by  selection  and  appropriate  season- 
ing, is  even  more  significant  when  the  very  light  weight  of  the  material 
is  remembered. 

Sudworth2  enumerates  the  following  palms  as  attaining  to 
the  dignity  of  trees  in  the  United  States: 
Sargent  Palm  (Pseudophcenix  sar-        Cabbage    Palmetto    (Sabal    pal- 

gentii) .  metto) . 

Fanleaf  Palm  (Washingtonia  fill-        Silvertop  Palmetto  (Thrinax  mi- 

fera) .  crocarpa) . 

Royal  Palm  (Oreodoxa  regid).  Silktop  Palmetto  (Thrinax  parvi- 

flora}. 

Mexican  Palmetto  (Sabal  mexi- 
cand) . 

1  Many  Palms  seen  at  pleasure  resorts  in  the  South  have  been  transplanted 
and  are  not  native  in  those  localities. 

2  "Check  List"  (U.  S.  Forestry  Bulletin  No.  17). 


226  ORGANIC  STRUCTURAL  MATERIALS 

Washington  Palm.  Washingtonia  fill/era  Wendl. 

Fan  leaf  Palm.  Neowashingtonia  filamentosa  Wendl. 

NOMENCLATURE  (Sud worth). 

Fanleaf  Palm,  Washington  Palm,  California  Fan  Palm,  Arizona  Palm, 
Desert  Palm  (Cal.).  Wild  Date  (CaL). 

LOCALITIES. 
California. 

FEATURES  OP  TREE. 

Thirty  to  sixty  feet  in  height;  one  and  one-half  to  three  feet  in  diameter; 
the  fan-shaped  leaves  rise  in  a  tuft  from  the  summit  of  the  trunk;  the 
largest  of  the  United  States  palms. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 
Light  greenish-yellow  to  dark  red;  unstable,  fibrous,  and  coarse. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft,  light,  shrinks  in  seasoning,  unstable,  hard  to  work. 

REPRESENTATIVE  USES  OF  WOOD. 
Fuel. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

32. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 

REMARKS. 

This  is  the  most  popular  of  the  palms  used  in  California  for  landscape 
effects.  The  wood  has  but  little  value,  but  the  light,  tough,  flexible, 
and  stringy  leaf -stalks  possess  characteristics  that  are  worthy  of  notice. 
The  results  of  experiments  upon  seasoned  stalks  are  noted  in  the  pre- 
ceding introduction.  The  name  "Wild  Date"  should  not  cause  these 
trees  to  be  confused  with  true  Date  Palms  (Phwnix  dactylifera). 


Date  Palm  (Phcenix  dactylifera).  These  trees,  which  grow  in  semi- 
tropical  regions  in  the  East,  have  been  naturalized  in  Arizona,  California, 
and  Florida.  In  the  East,  the  Date  Palm  is  valued  not  only  because  it 
yields  fruit,  syrup,  and  vinegar,  but  because  its  wood  is  employed  in  car- 
pentry and  simple  furniture;  the  leaves  are  used  in  making  fans,  baskets, 
cord,  and  paper.1 

1  "Arabia,"  Zwemer;  Swingle  (Year  Book,  United  States  Department  of 
Agriculture,  1900,  pp.  453,  490);  Tourney  (Arizona  Experiment  Station, 
Bulletin  No.  29). 


NON-BANDED  TRUNKS  AND  WOODS  227 

Cabbage  Palmetto.  Sahal  palmetto  Walt. 

NOMENCLATURE  (Sudworth). 

Cabbage      Palmetto,      Palmetto         Cabbage  Tree  (Miss.,  Fla.). 
(N.  C.,  S.  C.).  Tree  Palmetto  (La.). 

LOCALITIES. 

Central- Atlantic,  South  Atlantic,  and  Gulf  Coasts  of  the  United  States; 
the  West  Indies. 

FEATURES  OF  TREE. 

Thirty  to  forty  feet  in  height;  one  to  two  and  one-half  feet  in  diameter. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 
Light  brown;  fibrous  and  coarse. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Soft  and  light;  repels  marine  wood-borers. 

REPRESENTATIVE  USES  OF  WOOD. 
Used  locally  for  piles  and  docks. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

27. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 
REMARKS. 

Other  Palmettoes  grow  in  the  United  States.  Among  them  are  the 
Silver  Thatch  or  Silktop  Palmetto  (Thrinax  parvi  flora),  the  Prickly  Thatch 
or  Silvertop  Palmetto  (Thrinax  microcarpa),  and  the  Mexican  Palmetto 
(Sabal  mexicana). 


228  ORGANIC  STRUCTURAL  MATERIALS 

YUCCA 

Yucca 

This  genus  includes  about  thirty  species  and  many  varieties. 
Of  the  species  which  grow  in  the  United  States,  the  Tree  Yucca 
or  Joshua  tree  and  eight  others  assume  the  habit  and  attain  the 
size  of  small  trees.  The  Yuccas  are  among  the  exceptional  Mono- 
cotyledons that  increase  in  diameter  through  the  instrumentality 
of  a  cambium  layer.1  Several  of  the  Yuccas  are  cultivated 
because  of  their  beautiful  lily-like  flowers. 

Yucca  wood  is  coarse  and  fibrous.  Direct  vertical  cleavage 
is  lacking.  The  fibers  interlace  so  that  thin  sheets  of  rotary  cut 
wood  can  be  selected  which  bend  almost  as  readily  as  thick  felt. 
Yucca  wood  is  used  in  special  objects  such  as  souvenirs,  splints 
and  artificial  limbs.  Eight  species  noted  by  Sudworth  are  as 
follows : 

Joshua  tree  (Yucca  arborescens) .  Aloe-leaf  Yucca  (Yucca  aloifolid). 

Spanish    Bayonet    (Yucca    trecu-  Broadfruit  Yucca  (Yucca  macro- 

leana) .  car  pa} . 

Spanish  Dagger  (Yucca  gloriosa).  Schott  Yucca  (Yucca  brevifolia). 

Mohave  Yucca  (Yucca  mohaven-  Yucca  (Yucca  constricta}. 

sis) . 


See  also  "Textbook  of  Botany,"  Strasburger  (p.  145). 


NON-BANDED  TRUNKS  AND  WOODS  229 

Yucca  arbor  escens  Ton. 


Joshua-tree,  Yucca. 


NOMENCLATURE  (Sudworth). 

Joshua-tree,  The  Joshua,  Yucca,         Yucca  Cactus  (Cal.). 
Yucca  Tree  (Utah,  Ariz.,  N.  M., 
Cal.). 

LOCALITIES. 

Central  and  Lower  Rocky  Mountain  region. 

FEATURES  OE  TREE. 

Twenty-five  to  forty  feet  in  height;  six  inches  to  two  feet  in  diameter;  a 
thick,  outer  cover  or  bark. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Light  brown  to  yellowish  white;  fibrous  and  coarse;  interlaced  cellular 
arrangement. 

STRUCTURAL  QUALITIES  OF  WOOD. 

Light,  soft,  and  spongy;  flexible  in  thin  sheets. 

REPRESENTATIVE  USES  OF  WOOD. 

Small  objects,  as  souvenirs;  paper-pulp,  splints  and  artificial  limbs. 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 

23. 
MODULUS  OF  ELASTICITY. 

MODULUS  OF  RUPTURE. 

REMARKS. 

Artificial  limbs  are  made  by  bending  veneers  of  Yucca  wood  over  moulds; 
strong  cements  are  employed,  and  the  forms  that  result  are  strong, 
tough,  and  very  light.  The  sheets  of  flexible  Yucca  which  are  sold  in 
souvenir  stores  are  rotary  cut. 


230  ORGANIC  STRUCTURAL  MATERIALS 

BAMBOO 

Bambusa 

These  giant  grasses  grow  in  China,  Japan,  and  other  tropical 
and  semi-tropical  regions,  and,  in  some  places,  even  extend  over 
into  the  temperate  zone.  In  the  United  States  they  have  suc- 
ceeded as  far  north  as  the  Carolinas.1- 2 

Bamboo  stems  often  attain  heights  of  seventy  feet  and  diame- 
ters of  five  or  six  inches.  They  grow  with  surprising  rapidity; 
a  Philippine  specimen  grew  two  feet  in  three  days,3  while  some 
Florida  specimens  reached  heights  of  seventy-two  feet  in  a  single 
season.  The  stems  of  Bamboo  may  be  compared  with  those  of 
asparagus,  in  that  both  are  more  or  less  tender  when  young,  and 
much  more  hard  and  fibrous  when  old.  Stems  that  grow  in  a  few 
weeks  may  require  three  or  four  years  to  season  or  harden. 

Those  who  use  bamboo  value  it  highly.  The  pieces  are 
often  employed  without  splitting.  Sometimes,  while  yet  green, 
they  are  split  and  flattened  into  rough  boards,  which,  although 
they  split  everywhere  nevertheless  hold  together.  Johnson 
notes  that  "  Bamboo  is  just  twice  as  strong  as  the  strongest  wood 
in  cross-bending,  weight  for  weight,  when  the  wood  is  taken  in 
specimens  with  square  and  solid  cross-sections."4  The  manipu- 
lation of  this  valuable  material  is  not  yet  understood  in  the 
United  States,  but  some  of  the  many  ways  in  which  it  is  used 
abroad  are  summarized  as  follows:5 

"The  Chinese  make  masts  of  it  for  their  small  junks,  and  twist  into 
cables  for  their  larger  ones.  They  weave  it  into  matting  for  floors, 
and  make  it  into  rafters  for  roofs.  They  sit  at  tables  on  bamboo  chairs, 
eat  shutes  of  bamboo  with  bamboo  chop-sticks.  The  musician  blows 
a  bamboo  flute,  and  the  watchman  beats  a  bamboo  rattle.  Criminals 
are  confined  in  a  bamboo  cage,  and  beaten  with  bamboo  rods.  Paper 
is  made  of  bamboo  fiber,  and  pencils  of  a  joint  of  bamboo,  in  which  is 
inserted  a  tuft  of  goat's  hair." 

1  "Grasses.  This  is  one  of  the  largest  and  probably  one  of  the  most  use- 
ful groups  of  plants,  as  well  as  one  of  the  most  peculiar.  It  is  worldwide  in  its 
distribution,  and  is  remarkable  in  its  display  of  individuals,  often  growing  so 
densely  over  large  areas  as  to  form  a  close  turf.  If  the  grass-like  sedges  be 
associated  with  them  there  are  about  six  thousand  species,  representing 
nearly  one-third  of  the  Monocotyledons.  Here  belong  the  various  cereals, 
sugar  canes,  bamboos,  and  pasture  grasses,  all  of  them  immensely  useful 
plants"  ("Plants,"  Coulter,  pp.  240-241). 


NON-BANDED  TRUNKS  AND  WOODS  231 

2Fernow  notes  that  "In  addition  to  the  genus  Bambusa,  the  genera 
Arundinaria,  Arundo,  Dendrocalamus,  and  Guadua  are  the  most  important" 
(United  States  Forestry  Bulletin  No.  11,  p.  29). 

3  "Inhabitants  of  the  Philippines,"  Sawyer  (Scribner,  1900,  p.  5). 

4  "Materials  of  Construction"  Johnson  (John  Wiley  &  Sons,  1897,  p.  689). 

5  "Cycle  of  Cathay,"  Martin  (Fleming  H.  Revell  Company,  1899,  p.  172). 
See  also  "New  Granada,"  Holton  (Harper  Bros.,  1857,  p.  109);  "Bamboo 
and  its  Uses,"  Kurz   (Calcutta,   1876);  "The  Bamboo  Garden,"  Mitford 
(Macmillan,  1896);  "Japanese  Bamboos,"  Fairchild  (United  States  Bureau 
Plant  Industry,  Bulletins  Nos.  42-43) ;  etc.,  etc. 


232  ORGANIC  STRUCTURAL  MATERIALS 

Bamboo.  Bambusa  vulgaris 

NOMENCLATUEE. 

Bamboo  (local  and  common  name). 

LOCALITIES. 

Widespread  throughout  the  tropics  and  semi-tropics;  acclimated  in 
Florida. 

FEATURES  OF  TREE. 

Seventy-five  feet  in  height;  four  to  six  inches  in  diameter;  glazed,  greenish, 
jointed  stems,  delicate  branches  and  leaves;  extensive  roots. 

COLOR,  APPEARANCE,  OR  GRAIN  OF  WOOD. 

Yellowish  brown;  fibrous  and  coarse;  moderately  thin  walls  surround  cen- 
tral canals  which  are  broken  by  joints. 

STRUCTURAL  QUALITIES  OF  WOOD. 
Light  and  elastic;  works  easily. 

REPRESENTATIVE  USES  OF  WOOD. 

Posts,  poles,  troughs,  pies,  utensils,  roofing,  frames  of  aeroplanes,  and 

paper. 

» 

WEIGHT  OF  SEASONED  WOOD  IN  POUNDS  PER  CUBIC  FOOT. 
Variable. 

MODULUS  OF  ELASTICITY. 
2,380,000  (Johnson's  "Materials  of  Construction,"  p.  689). 

MODULUS  OF  RUPTURE. 
27,400  (Johnson's  " Materials  of  Construction,"  p.    689). 

REMARKS. 

Bamboos  are  not  trees,  although  they  are  as  tall  as  trees,  but  may  be 
described  as  wood-producing  grasses.  Bamboos  grow  rapidly.  A  stem 
may  reach  its  full  height  in  a  single  year,  but  must  then  stand  for 
three  or  four  years  in  order  to  season  and  harden. 


Rattan.  Rattan  is  obtained  from  several  sources.  One  species  (Calamus 
rudentum)  is  a  climber,  the  stalks  of  which  although  not  over  one  inch  in 
thickness,  are  sometimes  three  hundred  or  more  feet  in  length  as  they  fall  and 
ascend  in  festoons  from  tall  trees.  Another  species  (Rhapis  flabelliformis) 
yields  erect  canes  which  grow  in  thick  tufts.  Pieces  obtained  from  both 
climbing  and  ground  rattans  are  tough,  light,  long,  strong,  and  pliable. 
Locally,  rattan  is  used  for  making  houses,  bridges,  matting,  hats,  baskets, 
and  cordage.  In  most  civilized  countries,  split  rattan  is  superseding  willow 
for  furniture,  fancy  carriage  bodies,  chair  bottoms,  and  the  like.  The  best 
rattan  comes  from  Borneo. 


CHAPTER  IX 

SPECIAL  PROPERTIES  OF  WOODS  DUE  TO  THEIR  ORGANIC  ORIGIN. 
CHEMICAL  COMPOSITION  OF  WOODS.  PHYSICAL  PROPER- 
TIES OF  WOODS:  DESCRIPTIONS  OF  WEIGHTS  AND  MODULI 
EMPLOYED.  MOISTURE  IN  WOODS;  INFLUENCE  OF  MOIS- 
TURE, ANTISEPTICS,  AND  HEAT  UPON  THE  PHYSICAL  PROP- 
ERTIES OF  WOODS 

All  materials  are  studied  from  the  viewpoints  of  chemical 
composition  and  of  physical  properties,  but  organic  materials 
are  also  studied  from  the  viewpoint  of  special  or  additional 
properties  due  to  their  organic  origin.  It  is  because  of  these 
additional  traits  or  properties  that  wood  and  other  organic 
materials  are  more  complex  and  variable  than  inorganic  materials. 

SPECIAL    PROPERTIES    OF    WOODS    DUE    TO    THEIR    ORGANIC 

ORIGIN 

Cellular  structure,  inflammability  at  ordinary  temperatures, 
and  the  qualities  that  attract  and  nourish  micro-organisms  have 
no  counterparts  among  the  inorganic  materials.  For  example, 
wood  and  other  organic  materials  as  a  class  take  fire  readily 
under  ordinary  conditions  and  often  liberate  volumes  of  inflam- 
mable gases  by  means  of  which  fires  are  spread,  whereas  stones 
and  metal  do  not.  Also  the  rotting  of  wood  is  due  to  the  activi- 
ties of  bacteria  which  do  not  attack  inorganic  materials. 

Besides  these  there  are  other  characteristics,  less  definite 
but  of  at  least  equal  importance.  It  is  the  result  of  "life"  or 
physiological  processes  upon  the  chemical  composition  and 
physical  properties  of  .woods  and  other  organic  materials,  that 
causes  these  materials  to  be  so  variable.  Not  only  do  chemical 
and  physical  properties  of  woods  vary  with  species,  but  they  also 
vary  with  the  age  and  health  of  individual  trees  from  which  the 
pieces  are  cut. 

CHEMICAL    COMPOSITION    OF    WOODS 

From  the  standpoint  of  chemistry  also,  woods  are  complex 
and  variable.  Outer  or  living  portions  of  a  tree  trunk  contain 

233 


234  ORGANIC  STRUCTURAL  MATERIALS 

nitrogeneous  food-materials  and  others,  such  as  starches  and 
sugars;  while  the  inner  parts,  in  which  life-processes  have 
ceased,  contain  other  substances.  The  chemical  composition  of 
wood  cut  from  young  trees  differs  to  some  extent  from  the 
chemical  composition  of  wood  cut  from  older  trees.  Variations 
are  also  due  to  species.  Chemical  Elements,  Organic  Com- 
pounds, and  Inorganic  Compounds  must  all  be  noted. 

Chemical  Elements. — Wood  is  composed  principally  of  carbon, 
oxygen,  hydrogen,  nitrogen,  potassium,  calcium,  magnesium, 
phosphorous,  and  sulphur.  The  relative  qualities  are  much  in 
the  order  named.  The  greater  part  of  all  wood  is  made  up  of 
carbon  and  oxygen.  These  elements  with  hydrogen  constitute 
about  ninety-seven  per  cent,  of  dry  wood.1 

Ordinary  woods  contain  about  25  per  cent,  by  weight  of  water.  The 
remainder  of  100  pounds  of  such  wood,  that  is  75  pounds,  contains  about 
37  pounds  of  carbon,  32  pounds  of  oxygen,  4  pounds  of  hydrogen,  and 
2  pounds  of  the  other  elements  together.  None  of  the  elements  noted 
above  are  taken  up  by  the  tree  in  the  form  or  combination  in  which 
.they  are  eventually  assimilated.  Carbon,  hydrogen,  and  oxygen  are 
obtained  jointly  from  carbon  dioxide  and  water.  Nitrogen  is  absorbed 
in  the  form  of  nitrate  and  to  a  limited  extent  as  ammonia;  while  potash, 
calcium,  magnesium,  phosphorus,  and  sulphur  are  taken  up  in  the 
mineral  form.2 

Organic  Compounds. — Wood-substances  must  be  distinguished 
from  the  secretions  that  permeate  them.  The  cells,  of  which  all 
woods  are  composed,  are  made  up  as  follows:  (1)  The  walls  of 
the  cells  include  bundles  of  a  definite  substance  known  as  cellu- 
lose. (2)  The  bundles  of  cellulose  are  embedded  in  materials 
known  collectively  as  lignin.  (3)  The  cells  normally  contain 
such  substances  as  water,  protoplasm,  gums,  resins,  tannin, 
etc.,  etc. 

Cellulose. — This  is  the  substance  of  which  the  walls  of  all 
plant-cells  are  commonly  composed.  Flax  fiber  and  cotton  wool 
are  almost  pure  cellulose.  The  chemical  formula  for  cellulose, 
which  is  C6HioO5  or,  better  still  (C6Hi0O5)n,  is  the  same  as  that 
of  starch,  but  cellulose  differs  from  starch  in  that  it  resists 
alcoholic  fermentation.  Plants  themselves,  however,  and  the 

1  Wood  dried  at  about  300°F.  contains  about  49  per  cent,  of  carbon,  about 
44  per  cent,  of  oxygen,  about  4  per  cent,  of  hydrogen  and  about  3  per  cent,  of 
the  other  elements  noted.     See  also  "Timber,"  Roth  (United  States  Division 
of  Forestry,  Bulletin  No.  10,  p.  51),  etc. 

2  See  also  "Outlines  of  Botany,"  Leavitt,  pp.  229-239. 


CHEMICAL  COMPOSITION  OF  WOODS  235 

fungi  that  cause  decay  are  both  able  to  convert  cellulose  into 
starch  and  then  change  the  starch  into  the  various  forms  of 
sugar.1 

Lignin. — At  first  the  cells  are  soft  and  delicate,  but  eventually 
the  cell-walls  become  tough  and  woody  and  the  protoplasm 
disappears.  These  changes  are  due  to  the  appearance  of  the 
lignin  and  the  process  is  known  as  lignification. 

Lignin  is  harder  and  more  elastic  than  cellulose.  It  forms 
the  characteristic  part  of  the  woody-cell  and  a  large  part  by 
weight  of  ordinary  wood.2  The  chemical  composition  has  not 
been  satisfactorily  established,  but  is  variously  given  as  Ci8H2oO8 
and  CigHigOs.  Lignin  differs  from  cellulose  principally  in  its 
proportion  of  carbon. 

It  is  not  known  whether  the  composition  of  lignin  is  the  same 
in  all  woods.  The  difference  between  hardwoods  and  softwoods 
seems  to  bear  some  relation  to  differences  in  proportions  of 
cellulose  and  lignin  rather  than  to  differences  in  the  composition 
of  these  compounds.  As  a  general  rule  the  harder  the  wood  the 
larger  is  the  proportion  of  lignin. 

Associated  Materials. — Chemical  differences  due  to  species  are 
influenced  less  by  the  differences  that  exist  in  the  walls  of  the 
cell-structures  than  by  the  differences  that  exist  in  the  composi- 
tion of  the  materials  that  are  contained  in,  or  are  associated  with, 
the  cell-structures.  The  composition  of  the  walls  is  fairly  con- 
stant for  all  species,  but  the  composition  of  the  numerous  gums, 
resins,  tannin,  and  other  associated  materials  is  not  constant.3 

Sap. — This  is  as  necessary  to  plant  life  as  blood  is  to  animal  life. 
The  ascending,  or  " crude"  sap,  contains  various  minerals  and  nitroge- 
nous nutriment  derived  principally  from  the  soil,  while  the  descending, 
or- "  elaborated "  sap,  contains  the  more  complex  organic  preparations 
that  have  been  completed  in  the  foliage  through  the  instrumentality  of 
the  chlorophyll.  The  influence  of  sap  on  decay  is  considerable.  In 
the  sap  are  sugary  and  other  substances  that  attract  and  foster  the 
microorganisms  that  cause  decay.  It  is  the  presence  of  watery  sap 
that  makes  necessary  the  curative  processes  included  under  the  term 
"  seasoning." 

l" Timber,"  Roth  (United  States  Forestry  Division,  Bulletin  No.  10, 
p.  51). 

2  Lignin  is  contained  in  and  forms  the  characteristic  part  of  bast-cells. 

3  See  also  " Microchemistry  of  Plant  Products"  Stevens  ("Plant  Anat- 
omy," pp.  330-367);  United  States  Dispensatory;  etc. 


236  ORGANIC  STRUCTURAL  MATERIALS 

Protoplasm. — The  viscid  semi-fluid  substance  that  exists  within  young 
cells  contains  carbon,  hydrogen,  oxygen,  and  nitrogen,  with  traces  of 
sulphur,  phosphorus,  etc.  This  is  the  substance  in  which  all  plant- 
structures  originate.  The  name  is  from  the  Greek  protos  (first)  and 
plasma  (formed  matter).1 

"The  albuminous  substances  which  compose  protoplasm  differ  from 
the  carbohydrates  produced  by  assimilation,  in  containing  a  consider- 
able proportion  of  nitrogen  often  with  some  sulphur  and  phosphorus. 
It  is  in  the  formation  of  these  nitrogenous,  or  albuminous,  matters  that 
the  nutrient  mineral  salts  are  put  to  use.  Where  this  final  step  in  the 
production  of  proteid  matter  is  taken  is  not  definitely  known.  It  may 
be  that  it  is  in  the  green  tissue  of  the  leaf,  or  it  may  be  at  all  growing 
points."2 

Inorganic  Compounds. — The  mineral  constituents  of  wood  are 
the  parts  that  have  been  absorbed  from  the  soil  and  then  pre- 
pared for  assimilation  in  the  foliage.  Much  of  this  mineral 
matter  remains  in  the  foliage  and  is  returned  again  to  the  soil 
when  the  leaves  fall  in  the  autumn,  so  that  the  net  loss  to  the  soil, 
caused  by  the  tree,  is  inconsiderable.  The  quantity  of  mineral 
matter  retained  in  the  tree  is  very  small  when  compared  with 
the  quantity  of  carbon  that  is  gathered  by  the  tree  from  the 
atmosphere. 

The  principal  inorganic  compounds  present  in  wood  are  sul- 
phates, phosphates,  chlorides,  and  silicates  of  potash,  calcium, 
and  magnesium,  and  frequently  nitrates  of  these  latter  elements. 
In  addition,  the  basic  elements,  particularly  potash  and  calcium, 
may  be  found  combined  with  organic  acids,  such  as  citric,  malic, 
tartaric,  and  oxalic.  The  larger  number  of  chemical  elements 
are  within  this  group,  but  their  total  quantity  is  insignificant. 
The  quantity  varies  between  one-half  of  one  per  cent,  and  five 
per  cent.,  according  to  soil,  climate,  and  other  factors.  The 
average  is  about  three  per  cent. 

When  wood  is  heated,  about  one-fourth  of  its  weight  is  given 
off  as  water.  The  volatile,  inflammable  gases  then  separate 
from  the  carbon  which  burns  and  releases  the  mineral  matter  as 
ash.  The  principal  inorganic  compounds  found  in  ash,  as  dis- 
tinct from  wood,  are  sulphates,  carbonates,  silicates,  and  chlo- 
rides of  potash,  calcium  and  magnesium,  and  usually,  considerable 

1  "Wood,"  Boulger  (London,  Second  Edition,  pp.  5  and  6.). 

2  Outlines  of  Botany,"  Leavitb  (p.  236). 


PHYSICAL  PROPERTIES  OF  WOODS  237 

quantities  of  free  lime  also.     The  sulphates  and  carbonates  of 
potash  and  calcium  usually  predominate.1 

PHYSICAL  PROPERTIES  OF  WOODS 

It  is  necessary  to  distinguish  between  the  physical  properties 
of  woods  and  the  physical  properties  of  stones  and  metals.  The 
variations  due  to  life  processes,  age,  and  other  physiological 
causes  noticeable  in  the  properties  of  woods,  are  without  equiva- 
lents among  the  properties  of  the  inorganic  materials. 

The  cellular  structure  of  wood,  and  its  influence  upon  physical 
properties,  must  be  constantly  remembered.  This  influence  is 
due  to  (a)  the  character  of  the  cell-elements  of  which  wood  is 
composed,  (6)  the  arrangement  of  the  cell-elements,  and  (c)  the 
characteristics  and  quantities  of  compounds,  such  as  water, 
that  are  often  associated  with  the  cell-structures  without  being 
actually  part  of  them. 

The  subject  will  be  divided  as  follows:  (1)  The  physical 
properties  themselves  will  be  enumerated  or  described.  (2) 
The  attempts  that  have  been  made  to  measure  these  properties 
as  they  exist  in  woods  will  be  considered.  (3)  The  changes 
produced  by  certain  agents  will  be  noted. 

DESCRIPTIONS  OF  PHYSICAL  PROPERTIES.— The  first  or 
qualitative  part  of  the  subject  is  not  difficult.  Some  important 
properties  are  Strength,  Rigidity,  Elasticity,  Resilience,  Hard- 
ness, Ability  to  Hold  Fastenings,  Weight,  Specific  Gravity, 
Density  and  Porosity,  Conductivity  and  Resonance. 

Strength. — Strength  has  two  meanings.  There  is  the  general 
meaning  and  the  meaning  as  the  word  is  used  in  mechanics. 
In  the  latter  case,  strength  refers  to  properties  by  which  resistance 
is  offered  to  the  application  of  outside  forces.  An  outside  force 
is  opposed  by  an  inside  resistance,  and  any  change  that  may  take 
place  in  the  shape  of  the  body  to  which  the  force  is  applied  is 
referred  to  as  a  "deformation." 

The  five  kinds  of  deformation  commonly  recognized  are  extension, 
compression,  bending,  twisting,  and  shearing.  Extension  and  compres- 
sion are  results  of  direct  forces  acting  parallel  to  the  axis  of  the  specimen, 
while  bending  and  twisting  are  due  to  forces  that  are  perpendicular  to 
the  axis  of  the  specimen.  Shearing  may  occur  under  the  application  of 
forces  longitudinally  or  transversely.  A  deformation  is  said  to  be  "  elas- 
— 


See  chapter  entitled  "  Destruction  of  Wood  by  Burning." 


238  ORGANIC  STRUCTURAL  MATERIALS 

tic"  when  the  body  in  which  the  deformation  takes  place  tends  to  recover 
its  original  form  after  the  force  that  caused  the  deformation  has  ceased 
to  act. 

The  resistance  offered  to  the  forces  that  cause  any  or  all  of  the  forms 
of  deformation  is  known  as  Strength.  A  material  is  said  to  be  strong, 
or  it  is  said  to  possess  a  certain  amount  of  tensile  strength,  or  a  certain 
amount  of  compressive  strength  as  the, case  may  be.  The  term  elastic 
strength  is  used  to  denote  the  resistance  that  is  offered  to  forces  that 
produce  the  greatest  amount  of  elastic  deformation.  The  ultimate 
strength  of  any  material  is  the  greatest  resistance  that  the  material  can 
offer  to  any  kind  of  deformation. 

Modulus  of  Elasticity. — Within  certain  limits,  a  definite  relation  exists 
between  the  resistance  that  develops  in  a  body  and  the  deformation 


FIG.  31. — Machine  for  testing  light  wooden  beams.1 

that  accompanies  it.  It  happens  that  within  these  limits,  the  ratio 
between  the  unit-resistance  and  the  unit-deformation  in  tension,  is  usu- 
ally the  same  as  the  similar  ratio  in  compression.  This  important  ratio 
is  known  as  the  "  Modulus  of  Elasticity." 

The  Modulus  of  Elasticity  expresses  a  law,  first  announced  by  Robert 
Hooke  in  1675,  that  every  solid  is  perfectly  elastic  up  to  a  certain  limit 
known  as  the  elastic  limit.  The  proportion  is  expressed  as  follows: 
The  elongation  or  compression  of  a  specimen  one  inch  in  sectional  area: 
the  original  length  of  that  specimen:: the  weight  necessary  to  produce  the 
elongation  or  compression:  the  weight  that  would,  theoretically,  produce  an 
elongation  equal  to  the  original  length  of  the  specimen;  or 
The  Modulus  of  Elasticity  = 

Load  per  unit  of  cross-section 


E 


Elongation  or  compression  per  unit  of  length 


1  Tinius  Olsen,  Philadelphia,  Pa. 


PHYSICAL  PROPERTIES  OF  WOODS  239 

PI 

or  E  =  —  -  in  which  E  =  The  Modulus  of  Elasticity  in  pounds  per  square 
Ae 

inch,  P  =  the  total  load  in  pounds,  I  =  the  length  in  inches,  A  =  the 
area  of  cross-section  in  square  inches,  and  e  =  the  elongation  in  inches. 

The  meaning  of  The  Modulus  of  Elasticity  may  also  be  expressed  by 
the  statement  that  it  is  the  weight  or  force  that  would  elongate  a  speci- 
men of  unit-area  to  twice  its  original  length,  if  the  specimen  remained 
perfectly  elastic. 

The  Modulus  of  Elasticity  of  any  material  is  determined  experimen- 
tally with  the  aid  of  machines  prepared  for  that  purpose.  Typical  speci- 
mens are  selected,  measured  and  then  subjected  to  loads  sufficient  to 
cause  deformations.  The  loads  and  deformations  are  measured  and  the 
moduli  are  found  by  proportion  as  above. 


FIG.  32. — Machine  for  testing  heavy  wooden  beams.1 

Modulus  of  Rupture. — This  is  another  measure  of  primary  importance. 
This  modulus  for  tension,  compression,  or  shear,  is  the  load  that  will 
rupture  a  bar  of  unit-section  of  the  material  in  question.  In  other 
words,  it  is  the  maximum  unit-stress  sustained  by  the  material  just 
before  rupture,  or 
Modulus  of  Rupture  = 

Maximum  load  in  pounds 

l\i  =  • —  • 

Cross-sectional  area  of  specimen  in  square  inches 

Rigidity. — There  is  the  general  meaning,  and  the  definition 
as  the  word  is  sometimes  used  in  mechanics  and  engineering. 

General  Meaning. — Rigidity  is  here  the  opposite  of  flexibility.  A 
rigid  body  is  one  that  is  tense  or  stiff.  Such  a  body  is  not  easily  de- 
formed. From  this  point  of  view,  rigidity  and  stiffness  are  the  same. 

1  Tinius  Olsen,  Philadelphia,  Pa. 


240 


ORGANIC  STRUCTURAL  MATERIALS 


Engineering  Definition. — Rigidity  is  the  property  by  which  a  body 
resists  change  of  form  when  acted  upon  by  an  external  force;  the  amount 
of  force  and  the  nature  of  the  deformation  are  not  regarded.  The  form 
of  a  perfectly  rigid  body  could  not  be  changed  by  the  application  of  an 
external  force,  but  a  perfectly  rigid  body  does  not  exist.  The  distinction 
between  rigidity  and  stiffness  as  these  terms  are  used  in  mechanics, 
should  be  noted.  From  this  point  of  view,  rigidity  is  the  property  by 
which  a  body  resists  deformation,  regardless  of  the  nature  of  the  de- 
formation; while  stiffness  is  the  property  by  which  a  body  resists  elastic 
deformation. 


FIG.  33. — Olsen  machine  for  making  tortion  tests. 

Elasticity. — Elasticity  has  a  popular  meaning,  a  general  mean- 
ing, and  a  meaning  as  the  word  is  used  in  physics,  engineering, 
and  mechanics. 

Popular  Meaning. — The  term  elasticity  is  often  used  to  denote  the 
property  by  which  a  body  sustains  a  large  amount  of  deformation  and 
regains  its  original  form  after  the  force  that  caused  the  deformation  has 
been  removed.  Indiarubber  is  a  very  elastic  material  from  this  point 
of  view. 

"General  Meaning. — Elasticity  is  the  property  by  which  a  material 
tends  to  resume  its  original  form  after  the  forces  that  caused  it  to  leave 
the  original  form  have  ceased  to  act.  The  difference  between  this  defi- 
nition and  the  one  that  precedes  it  lies  in  the  fact  that  in  the  present 
case  the  amount  of  the  deformation  is  not  material. 

Meaning  in  Physics. — A  body  is  said  to  be  perfectly  elastic  when  the 
work  done  in  producing  a  deformation  in  the  body  equals  the  work  done 


PHYSICAL  PROPERTIES  OF  WOODS  241 

when  the  body  recovers  its  original  form.  A  perfectly  elastic  body  does 
not  exist.  There  is  always  some  motion  between  adjacent  particles 
whenever  a  material  suffers  deformation  and  this  causes  friction  and  loss 
of  work.  Ivory  is  more  elastic  than  Indiarubber  from  this  point  of 
view. 

Meaning  in  Engineering. — The  material  of  which  a  body  is  composed 
is  said  to  be  perfectly  elastic  for  all  forces  equal  to  or  less  than  a  certain 
applied  force,  when  the  body  having  been  deformed  by  that  force  suc- 
ceeds in  recovering  its  original  form  after  the  force  has  ceased  to  act. 

Resilience. — This  property  is  intimately  connected  with 
elasticity.  The  name  resilience  has  several  meanings,  as  springi- 
ness, the  power  of  springing  back,  and  the  power  of  resuming  a 
former  shape.  Resilience  also  stands  for  the  amount  of  work 
accomplished  by  a  body  when  recovering  from  a  deformation. 

Johnson1  defines  resilience  as  "the  springing  back  of  a  deformed  body 
after  the  deforming  force  has  been  removed.  As  used  in  mechanics, 
however,  it  is  the  work  done  by  the  body  in  this  springing  back,  which 
is  the  same  as  the  work  done  on  the  body  in  deforming  it,  so  long  as 
this  is  inside  the  elastic  limits.  Beyond  the  elastic  limit,  the  work  of 
deformation  always  exceeds  the  work  given  back  by  the  body.  The 
body  then  does  not  fully  recover  its  initial  position,  shape  or  dimensions. 
Sometimes  the  work  of  deformation,  whether  inside  or  beyond  the  elastic 
limit,  is  spoken  of  as  the  resilience,  but  this  is  improper.  The  resilience 
proper  is  the  amount  of  work  or  energy  in  foot-pounds,  which  can  be  stored 
in  an  elastic  body  up  to  a  given  stress  per  square  inch,  and  which  can  be 
given  out  again  by  the  body  as  useful  work,  if  desired." 

Hardness. — This  is  the  property  by  which  a  material  resists 
indentation  and  abrasion.  Hardness  is  influenced  by  density 
and  weight.  Lignumvitse,  greenheart,  osage  orange,  and  some 
of  the  eucalypts  are  very  hard  woods.  Poplar  and  white  cedar 
are  soft  woods. 

Resistance  to  abrasion  has  been  determined  by  pressing  blocks  of 
wood  against  revolving  discs  covered  with  sandpaper.  The  amounts 
worn  from  the  ends  of  the  blocks  have  been  taken  as  measures  of  the 
hardness  of  the  specimens.  The  proper  abrasive,  the  speed  of  the  disc, 
the  pressure  and  other  details  are  important.  Indentation  testing  ma- 
chines are  also  used.  Tests  to  determine  the  hardness  of  commercial 
woods  have  been  begun  by  the  United  States  Department  of  Agriculture. 

1  "Materials  of  Construction,"  p.  75,  1908  edition. 


242 


ORGANIC  STRUCTURAL  MATERIALS 


Ability  to  Hold  Fastenings. — This  characteristic  property  con- 
tributes very  largely  to  the  usefulness  of  wood  as  a  material  of 
construction  and  may  also  be  a  measure  of  durability,  as  is  shown 
in  the  case  of  railway  ties  which  often  fail  because  they  cannot 
hold  spikes.  The  spikes  are  driven  so  many  times  that  the 
ends  of  otherwise  good  ties  become  cut  and  useless.1 


FIG.  34. — Displacement  caused  FIG.  35. — Displacement  caused 
by  common  spike.  Photograph,  by  screw  spike.  Photograph, 
Spencer  Otis  Company.  •  Spencer  Otis  Company. 

The  ability  to  hold  fastenings  is  due  principally  to  friction;  in  some 
cases,  although  to  a  less  extent,  it  may  also  be  due  to  adhesion. 

Nails  cut,  break,  bend,  and  compress  the  fibers  of  the  pieces  into 
which  they  are  driven.  The  mutilated  fiber-extremities  react  and  pre- 
sent roughened  surfaces  that  press  upon  the  surfaces  of  the  nails.  Pres- 
sure is  also  exerted  by  the  fibers  that  have  been  bent  and  forced  aside. 

The  forces  required  to  withdraw  nails  bear  some  resemblance  to  those 
required  to  drive  them  and  vary  with  the  character  of  the  nails,  the 
character  of  the  wood,  and  the  direction  of  penetration.  (1)  It  is 

1  European  engineers  sometimes  use  wooden  dowels  that  are  screwed  into 
spaces  cut  for  them  in  the  ties.  The  spikes  are  driven  into  the  dowels  and 
the  dowels  are  replaced  when  they  become  cut  so  that  they  cannot  longer 
hold  the  spikes.  (See  United  States  Forest  Division,  Bulletin  No.  50,  p.  64). 


PHYSICAL  PROPERTIES  OF  WOODS  243 

harder  to  drive  and  withdraw  rough,  blunt  nails  than  to  drive  and 
withdraw  nails  that  are  smooth  and  sharp.  (2)  Hard  woods  like  oak 
offer  greater  resistance  to  penetration  and  withdrawal  than  softer  woods 
like  poplar.  (3)  It  is  easier  to  drive  nails  with  the  grain  than  across  it, 
and  it  is  easier  to  draw  nails  that  have  been  driven  with  the  grain  than 
to  draw  those  that  have  been  driven  across  the  grain. 

A  series  of  experiments  upon  The  Holding  Power  of  Railroad  Spikes, 
conducted  at  the  University  of  Illinois,1  indicates  as  follows: 

1.  The  maximum  resistance  to  direct  pull  varies  from  6,000  pounds 
to  14,000  pounds  for  screw  spikes,  from  3,000  pounds  to  8,000  pounds 
for  ordinary  spikes  when  driven  into  untreated  timbers,  and  from  4,000 
pounds  to  9,000  pounds  for  ordinary  spikes  when  driven  into  treated 
timbers. 

2.  The  direct  pull  required  to  withdraw  ordinary  spikes  ^  inch  varies 
from  2,000  to  3,000  pounds  for  untreated  timbers,  and  from  2,500  to 
3,500  pounds  for  treated  timbers. 

3.  The  direct  pull  required  to  withdraw  ordinary  spikes  Y±  inch  varies 
from  3,000  to  5,400  pounds  for  untreated  timbers  and  from  3,800  to 
5,900  pounds  for  treated  timbers. 

4.  Timbers  having  loose  fiber-structures  have  lower  resistances  to 
direct  pull  than  timbers  having  compact  fiber-structures. 

5.  The  amount  of  withdrawal  which  must  occur  for  ordinary  spikes 
to  develop  the  maximum  resistance  is  less  for  soft  woods  than  for  hard 
woods. 

6.  Spikes  driven  into  treated  timbers  offer  a  greater  resistance  to 
direct  pull  than  spikes  in  untreated  timbers,  and  the  difference  between 
this  resistance  for  treated  and  untreated  timbers  is  greater  for  soft 
woods  than  for  hard  woods. 

7.  The  difference  in  the  resistance  to  direct  pull  for  the  different  sized 
spikes  in  use  (%6  inch,  i%2  inch,  and  %  inch)  is  very  small. 

8.  The  resistance  of  ordinary  spikes  to  direct  pull  varies  directly  as 
the  depth  of  penetration,  neglecting  the  tapering  point. 

9.  Blunt-pointed  and  bevel-pointed  spikes  have  a  slightly  greater  re- 
sistance to  direct  pull  than  chisel-pointed  spikes. 

10.  For  withdrawals  less  than  y±  inch,  ordinary  spikes  which  are 
driven  into  bored  holes  have  a  little  greater  resistance  to  direct  pull 
than  spikes  driven  in  the  ordinary  way. 

1  University  of  Illinois  Bulletin,  Vol.  Ill,  No.  18,  Webber. 

See  also  "Substitution  of  Metal  for  Wood  in  Railroad  Ties,"  Tratman 
(United  States  Forestry  Division,  Bulletin  No.  4,  1890);  "Crosstie  Forms 
and  Rail  Fastenings  with  Special  Reference  to  Treated  Timbers,"  von 
Schrenk  (United  States  Forestry  Bureau,  Bulletin  No.  50,  1904);  "Holding 
Force  of  Railroad  Spikes  in  Wooden  Ties,"  Hatt  (United  States  Forest 
Service,  Circular  No.  46,  1906). 


244 


ORGANIC  STRUCTURAL  MATERIALS 


11.  The  resistance  to  direct  pull  for  re-driven  spikes  is  from  60  to  80 
per  cent,  of  the  resistance  of  newly  driven  spikes. 

12.  The  efficiency  of  screw  spikes  to  resist  withdrawal  is  nearly  twice 
as  great  as  that  of  common  spikes. 

13.  The  resistance  of  %-inch  spikes  to  lateral  displacement  is  slightly 
greater  than  that  of  %6-inch  spikes. 

14.  The  resistance  to  lateral  displacement  increases  with  the  depth 
of  penetration,  but  the  increase  is  negligible  for  depths  of  penetration 
greater  than  4  inches. 

15.  Screw  spikes  are  more  efficient  than  ordinary  spikes  in  resisting 
lateral  displacement. 


!f£~£ 

•  •  -••••>•     •      -    ,;fj 


FIG.  36. — Metal  tie  plate. 
Photograph,  Spencer  Otis 
Company. 


FIG.  37. — Rail  resting  on  tie  plate.     Pho- 
tograph, Spencer  Otis  Company. 


Weight,  Specific  Gravity,  Density. — The  weight  of  a  body  is 
the  downward  or  specific  force  of  that  body.  The  specific 
gravity  of  a  piece  of  wood  is  the  ratio  of  the  weight  of  a  given 
bulk  of  that  wood  to  the  weight  of  an  equal  bulk  of  water. 
Density  and  weight  may  be  interchangeable. 

The  wood  tissues  in  the  cell-walls  of  all  species  weigh  about 
the  same ;  but  the  woods  themselves  vary  considerably.  Similar 
volumes  of  woods  of  different  species  contain  more  or  less  cell- 
wall  tissue  as  the  case  may  be.  The  greater  the  proportion  of 
cell  walls  and  the  smaller  the  proportion  of  air  spaces,  the 
greater  the  density,  and  therefore  the  weight  of  the  wood.  Den- 


PHYSICAL  PROPERTIES  OF  WOODS  245 

sity  and  weight  may  thus  be  indications  of  hardness  and  strength. 
On  the  other  hand,  the  smaller  the  proportion  of  cell-wall  mate- 
rial and  the  larger  the  proportion  of  air  spaces,  the  smaller  the 
density,  the  weight,  and  the  strength  of  the  wood.  Light  woods 
are  porous  and  buoyant.1 


FIG.  38. — Turner  impact  testing  machine. 

Not  only  does  the  weight  of  wood  depend  upon  the  character  and 
quantity  of  the  woody  tissue,  but  it  also  depends  upon  the  water,  gums, 
resins,  and  other  substances  that  may  be  associated  with  the  woody 
tissues.  The  principal  weight  variations  observed  in  woods  are  due  to 

1  See  index,  "Density  Test." 


246  ORGANIC  STRUCTURAL  MATERIALS 

the  presence  of  water.  Half  of  the  weight  of  live  sapwood  may  be  made 
up  in  this  way.  There  is  less  water  in  heartwood,  and  more  in  young 
and  vigorous  trees  than  in  those  that  are  older  and  less  healthy.  All 
trees  contain  more  sap  at  some  seasons  of  the  year  than  at  others. 
Woods  that  are  apparently  dry  contain  some  water.  The  influence  of 
water  is  so  important  as  to  warrant  further  attention.1 

As  indicated,  the  weight  of  dry  and  clean  wood  is  normally  a  sign  of 
strength.  A  heavy  piece  of  oak  is  usually  stronger  than  a  lighter  piece; 
and,  unless  the  extra  weight  is  due  to  abnormal  quantities  of  resin,  a 
heavy  piece  of  yellow  pine  is  stronger  than  a  piece  that  weighs  less. 

It  will  be  remembered  that  the  quantity  of  water  contained  in  a  piece 
of  wood  will  vary  with  the  proportions  of  sapwood  and  heartwood,  and 
with  the  state  of  the  weather.  The  proportion  of  water  in  wood  is  usu- 
ally greater  than  in  the  surrounding  air.  The  quantity  is  not  constant, 
but,  varying  with  humidity,  amounts  to  about  twelve  per  cent,  of  the 
weight  of  the  dry  wood.  The  weight  of  wood  is  usually  calculated  from 
small,  sound  specimens,  which  have  been  dried  in  a  kiln  at  a  tempera- 
ture of  100  degrees  C.  until  they  reach  a  weight  that  does  not  vary. 

The  comparative  weights  in  pounds  per  cubic  foot  of  some 
broadleaf  woods  are  as  follows : 

Balsa Ochroma  lagopus 7 

Cork  (from  cork  oak) Quercus  cuber 14 

Missouri  corkwood Leitneria  floridana 18 

White  Pine Pinus  strobus 24 

Catalpa Calalpa  speciosa 25 

Cypress Taxodium  distichum 29 

Douglas  Fir. . Pseudotsuga  mucronata 32 

Sycamore Platanus  occidentalis 35 

Longleaf  pine Pinus  palustris 38 

Maple Acer  saccharum 43  . 

Locust Robinia  pseudacacia 45 

Mahogany Swietenia  mahagoni 45 

Red  Oak Quercus  rubra 45 

White  Oak Quercus  alba 50 

Hickory Carya  alba 51 

Live  oak Quercus  virginiana 59 

Ironbark Eucalyptus  leucoxylon 70 

Lignumvitae Guajacum  sanctum 71 

Greenheart Nectandra  rodioei 72 

Ebony Diospyros  ebenum 73 

^ee  index,  under  "Moisture."  See  also  Roth,  United  States  Forestry 
Division,  Bulletin  No.  10. 


PHYSICAL  PROPERTIES  OF  WOODS  247 

Porosity,  Penetrability. — A  porous  substance  is  one  that  can  be 
penetrated  by  another  substance.  It  is  one  that  is  pervious  or 
full  of  pores.  Weight  and  density  are  both  influenced  by 
porosity. 

The  porosity  of  wood  depends  upon  the  character  and  arrange- 
ment of  the  cell-elements  of  which  it  is  composed,  and  also  upon 
the  characteristics  and  quantities  of  foreign  materials  that  may 
be  present,  such  as  water  and  resin;  and,  since  the  content  of  water 
may  vary,  permeability  may  vary  also. 

Heavy,  dense  woods  are  much  less  permeable  than  are  light, 
loose-structured  woods;  while  clean  and  seasoned  woods  are  more 
permeable  than  woods  that  are  resinous  or  green.  Sapwood  is 
more  permeable  than  heartwood.  A  study  of  the  porosity  of 
woods  is  closely  associated  with  a  microscopic  study  of  their 
cellular  structure.1  The  permeability  of  wood  has  an  important 
bearing  upon  its  response  when  treated  with  solutions  designed 
to  prevent  decay. 

A  series  of  experiments  conducted  to  determine  facts  with 
regard  to  the  permeability  of  woods  resulted  in  the  statements 
that  follow:2 

1.  "All  woods  in  the  fresh,  green  state  are  impenetrable  to  gases  even 
under  high  pressures,  except  through  the  open  vessels  in  the  angiosperms3 
and  the  resin-ducts  in  the  conifers  where  these  are  not  clogged  by  tyloses 
or  resin.     The  same  is  true  as  regards  liquids,  except  that  water  solu- 
tions may  gradually  seep  through  the  membranes.     Since  it  is  the  wood- 
fibers  and  the  tracheids  which  form  the  main  part  of  the  structure  of 
wood,  impregnation  of  the  vessels  or  resin-ducts  would  be  of  little  or  no 
value  of  itself  in  preservative  treatment.     The  above  is  due  to  the  fact 
that  every  cell  is  a  closed  vessel  completely  surrounded  by  its  primary 
wall. 

2.  Whenever   wood   seasons    (beyond   its   fiber   saturation   point), 
whether  naturally  or  by  artificial  means,  narrow  microscopical  slits 
occur  in  the  walls  of  the  fibers  and  tracheids  which  render  them  pene- 
trable to  gases  and  liquids.     These  slits  do  not  re-unite  when  the  wood  is 
re-soaked  although  they  may  close  up  somewhat.     The  greater  the  de- 
gree of  dryness,  the  more  penetrable  the  wood  becomes. 

3.  Steaming  green  wood  produces  a  somewhat  similar  effect  but  to  a 

1  American  Railway  Engineering  Association,  Bulletin  No.  107,  January, 
1909. 

2  American  Railway  Engineering  Association,  Bulletin  No.  120,  February, 
1910. 

3  Woods  from  Broadleaf  trees. 


248  ORGANIC  STRUCTURAL  MATERIALS 

less  degree  unless  the  wood  be  subsequently  dried  also.  The  reason 
then,  that  absolutely  green  wood  cannot  be  successfully  treated  with 
preservatives  is  due,  not  so  much  to  the  fact  that  the  wood  contains 
water,  but  because  the  cell-walls  are  unbroken  and  therefore  impene- 
trable. Just  what  pressure  these  walls  would  resist  it  is  impossible  to 
state,  but  it  seems  probable  that  it  would  run  into  the  thousands  of 
pounds  per  square  inch." 

The  influence  exerted  by  tyloses  upon  porosity  is  very  marked. 
These  obstructions,  which  exist  in  the  large  vessels  of  a  number 
of  the  broadleaf  woods  and  in  the  resin-ducts  of  some  of  the  needle- 
leaf  conifers,  and,  which  are  often  visible  to  the  unaided  eye, 
tend  to  block  up  the  passages  through  which  foreign  fluids,  such 
as  antiseptics,  are  otherwise  largely  introduced.  Weiss  separates 
some  of  the  broadleaf  woods  into  three  groups,  depending  upon 
the  presence  or  absence  of  tyloses,  as  follows:1 

Tyloses  Absent.  The  maples,  birches,  blue  beech,  flowering  dogwood, 
holly,  silverbell,  black  and  water  gums,  black  and  red  cherry,  basswood, 
persimmon,  honey  locust. 

Tyloses  Few.  Yellow  buckeye,  beech,  red  gum  (sap),  yellow  poplar, 
magnolias,  sycamore,  black  cottonwood,  eucalyptus  (blue  gum),  white 
and  Oregon  ashes,  and  the  elms. 

Tyloses  Abundant.  Large  tooth  aspen,  hardy  catalpa,  desert  willow, 
green,  pumpkin  and  blue  ash,  mocker  nut,  water  pignut,  shellbark, 
bitternut,  nutmeg  and  shagbark  hickories,  butternut,  black  walnut,  red 
mulberry,  blackjack,  white,  Garry,  overcup,  valley,  bur,  cow,  post  and 
swamp  white  oaks,  black  locust,  and  osage  orange. 

Cleavability.  —  When  applied  to  wood  this  term  denotes  the 
ease  with  which  the  longitudinal  fabric  of  the  wood  can  be 
separated.  The  cleavability  of  wood  is  opposed  by  cohesion  and 
by  some  phases  of  the  cellular  structure  of  the  wood.  Cleava- 
bility is  influenced  by  temperature.  It  is  less  when  it  is  extremely 
cold. 

Conductivity.  —  This  is  the  property  by  which  heat,  electricity, 
and  sound  are  transmitted  or  conveyed.  It  is  well  known  that 
wood  is  a  poor  conductor  of  heat  and  a  good  conductor  of  sound, 
particularly  in  the  direction  of  the  length  of  the  pieces. 

Dry  wood  is  an  almost  perfect  non-conductor  of  electricity, 
but  green  or  wet  wood  presents  a  comparatively  low  resistance 
to  the  passage  of  electricity.  The  results  of  experiments  con- 


examinations  by  Eloise  Gerry,  United  States  Forest  Products 
Laboratory. 


PHYSICAL  PROPERTIES  OF  WOODS  249 

ducted  to  determine  the  electrical  resistance  of  woods  treated 
with  zinc  and  other  preservatives  are  as  follows:1 

1.  The  resistance  of  timber  varies  directly  with  the  length  and  in- 
versely with  the  cross-section. 

2.  The  resistance  varies  almost  inversely  with  the  amount  of  moisture 
present,  between  the  limits  of  15  and  50  per  cent. 

3.  The  resistance  is  lowest  when  measured  along  the  grain,  and  highest 
when  measured  tangentially  to  the  growth-rings. 

4.  When  treated  with  a  soluble  salt  such  as  zinc-chloride,  the  resist- 
ance varies  approximately  inversely  as  the  amount  of  the  salt  present. 

5.  Treatment  with  such  a  soluble  salt  does  not  change  the  behavior 
of  the  resistance  with  respect  to  the  percentage  of  moisture  present. 
Only  the  amount  of  the  resistance  is  changed. 

6.  The  resistance  of  timber  varies  almost  inversely  with  the  tempera- 
tare  between  the  limits  of  zero  and  50  degrees  C. 

7.  The  resistance  of  non-porous  woods,  such  as  the  pines,  is  higher 
than  that  of  porous  woods,  such  as  the  oaks  and  red  gum. 

8.  Treatment  of  timber  by  different  creosote  processes  does  not 
greatly  change  the  natural  resistance  of  the  timber. 

9.  The  conductivity  of  wood  is  due  primarily  to  the  presence  in  the 
pores  of  an  electrolyte  formed  by  an  aqueous  solution  of  the  salts  found 
in  the  natural  timber,  or  of  these  salts  and  others  artificially  introduced. 

Conductivity  is  diminished  by  porosity  and  increased  by 
density  and  by  water.  It  is  less  when  the  wood  is  diseased. 

Resonance. — Strictly  speaking,  resonance  is  the  property  by 
which  sound  is  repeated  or  sustained.  Occurrences  in  other 
branches  of  physics,  as  electricity,  are  similar  to  those  in  acous- 
tics and  have  warranted  an  extension  of  the  term  to  include  cases 
in  which  sound  plays  no  part.  Hering  expresses  the  wider  mean- 
ing of  the  term  resonance  as  follows: 

"If  any  rhythmic  action  in  one  body  excites  rhythmic  action  of  like 
periodicity  in  another,  whether  in  connection  with  the  first  body  or 
apparently  separated  from  it,  the  second  body  is  said  to  be  in  resonance 
with  the  first." 

The  meaning  of  "resonance"  is  limited  to  the  acoustic  property 
when  the  word  is  used  in  connection  with  wood. 

Pores,  pith-rays,  and  other  irregularities  that  occur  in  broad- 
leaf  woods,  interfere  with  the  resonance  of  such  woods  and  for 
this  reason  broadleaf  woods  are  commonly  less  resonant  than  are 

1  "The  Electrical  Resistance  of  Timber,"  Butterfield,  Engineering  News, 
April  6,  1911. 


250  ORGANIC  STRUCTURAL  MATERIALS 

some  of  those  of  the  coniferous  series.  All  woods  are  more  reso- 
nant when  they  are  dry.  Spruce  is  one  of  the  most  resonant  of 
woods  and  is  used  for  sounding  boards  in  pianos  and  violins. 

"If  a  log  or  scantling  is  struck  with  the  axe  or  hammer,  a  sound  is 
emitted  which  varies  in  pitch  and  character  with  the  shape  and  size  of 
the  stick,  and  also  with  the  kind  and  condition  of  wood.  Not  only  can 
sound  be  produced  by  a  direct  blow,  but  a  thin  board  may  be  set  vibra- 
ting and  be  made  to  give  a  tone  by  merely  producing  a  suitable  tone  in 
its  vicinity.  The  vibrations  of  the  air,  caused  by  the  motion  of  the 
strings  of  the  piano,  communicate  themselves  to  the  board,  which  vi- 
brates in  the  same  intervals  as  the  string  and  re -enforces  the  note.  The 
note  which  a  given  piece  of  wood  may  emit  varies  in  pitch  directly  with 
the  elasticity,  and  indirectly  with  the  weight,  of  the  wood.  The  ability 
of  a  properly  shaped  sounding  board  to  respond  freely  to  all  the  notes 
within  the  range  of  an  instrument,  as  well  as  to  reflect  the  character  of 
the  notes  thus  emitted  (i.e.,  whether  melodious  or  not),  depends,  first, 
on  the  structure  of  the  wood  and  next  on  the  uniformity  of  the  same 
throughout  the  board.  In  the  manufacture  of  musical  instruments  all 
wood  containing  defects,  knots,  cross  grain,  resinous  tracts,  alternations 
of  wide  and  narrow  rings,  and  all  wood  in  which  summer  and  spring 
wood  are  strongly  contrasted  in  structure  and  variable  in  their  propor- 
tions, is  rejected,  and  only  radial  sections  (quarter-sawed,  or  split)  of 
wood  of  uniform  structure  and  growth  are  used. 

"The  irregularity  in  structure,  due  to  the  presence  of  relatively  large 
pores  and  pith-rays,  excludes  almost  all  our  broadleaved  woods  from 
such  use,  while  the  number  of  eligible  woods  among  conifers  is  limited 
by  the  necessity  of  combining  sufficient  strength  with  uniformity  in 
structure,  absence  of  too  pronounced  bands  of  summer  wood,  and  rela- 
tive freedom  from  resin.  < 

"Spruce  is  the  favored  resonance  wood;  it  is  used  for  sounding  boards 
both  in  pianos  and  violins,  while  for  the  resistant  back  and  sides  of  the 
latter,  the  highly  elastic  hard  maple  is  used.  Preferably  resonance  wood 
is  not  bent  to  assume  the  final  form;  the  belly  of  the  violin  is  shaped  from 
a  thicker  piece,  so  that  every  fiber  is  in  the  original  as  nearly  unstrained 
condition  as  possible,  and  therefore  free  to  vibrate.  All  wood  for  musical 
instruments  is,  of  course,  well  seasoned,  the  final  drying  in  kiln  or  warm 
room  being  preceded  by  careful  seasoning  at  ordinary  temperatures 
often  for  as  many  as  seven  years  or  more.  The  improvement  of  violins, 
not  by  age  but  by  long  usage,  is  probably  due,  not  only  to  the  adjust- 
ment of  the  numerous  component  parts  to  each  other,  but  also  to  a 
change  in  the  wood  itself,  years  of  vibrating  enabling  any  given  part 
to  vibrate  much  more  readily."1 

*"  Timber,"  Roth  (United  States  Division  Forestry,  Bulletin  No.  10, 
pp.  24,  25). 


PHYSICAL  PROPERTIES  OF  WOODS  251 

Hygroscopicity. — This  is  the  property  by  which  dry  wood 
absorbs  water  from  the  air,  loses  it  when  dried  again,  and  then 
gathers  new  supplies  when  the  wood  is  re-exposed.  Hygro- 
scopicity diminishes  the  value  of  wood,  since  variations  in  mois- 
ture are  accompanied  by  changes  in  volume.  A  door  will  stick 
during  the  summer  when  outdoor  air  has  free  access  to  the  house, 
but  will  loosen  during  the  winter  when  the  windows  are  closed 
and  the  house  is  heated.  Contraction  and  expansion  may  be 
repeated  so  many  times  as  to  interfere  with  strength.  A  piece  of 
wood  affected  in  this  manner  has  not  decayed  but  rather  may  be 
said  to  have  aged.  The  tendency  is  greatly  reduced  when  wood- 
work is  protected  with  oils,  paints,  and  varnishes. 

Color. — Color  is  a  physical  property.  This  is  so  regardless  of 
the  chemical  means  by  which  it  is  brought  about.  The  color  of 
wood,  which  is  due  to  the  presence  of  pigments  manufactured  by 
the  tree  during  its  lifetime,  differs  with  species,  and  is  more  or  less 
characteristic  of  them,  so  that  it  may  be  of  considerable  assist- 
ance in  identifying  woods. 

In  practically  every  species  the  wood  first  formed  is  almost  colorless. 
But  later,  as  the  wood  changes  from  sapwood  to  heartwood,  the  char- 
acteristic pigments  appear  in  the  heartwood.  Tints  frequently  vary  as 
woods  are  cut  from  younger  or  older  trees.  When  woods  are  exposed 
to  the  weather,  chemical  changes  take  place  in  the  pigments,  which  then 
become  darker.  Prolonged  immersion  in  water  also  causes  woods  to 
become  darker.  Some  pigments  are  of  such  a  character  that  they  can  be 
removed  when  the  woods  in  which  they  were  formed  are  soaked  in 
water,  and  many  pigments  removed  in  this  manner  are  used  as  dyes. 
Disease,  such  as  "  bluing,"  may  cause  colors  in  woods.1 

Color  may  or  may  not  be  desirable.  One  of  the  factors  that  causes 
many  woods  to  be  preferred  in  indoor  finish  is  color;  and,  where  natural 
color  is  lacking,  it  is  often  obtained  artificially  by  means  of  stains. 
Color  is  not  desirable  in  spokes,  handles,  and  wood  used  for  paper  pulp. 

MEASUREMENTS    OF    PHYSICAL    PROPERTIES.— This 

second  part  of  the  subject  is  more  difficult  than  the  first.  It  is 
easy  to  describe  qualities  as  such,  but  it  is  not  as  easy  to  measure 
such  qualities  serviceably  where  the  material  is  as  variable  as 
the  one  in  question. 

Not  only  do  wood-specimens  cut  from  trees  of  the  same  species 

1  See  also  "The  'Bluing'  and  the  'Red  Rot'  of  the  Western  Yellow  Pine," 
von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin  No.  36, 
1903). 


252  ORGANIC  STRUCTURAL  MATERIALS 

vary  with  age,  soil,  and  environment,  but  pieces  cut  from  the  same 
tree  vary  with  water,  imperfections,  and  proportions  of  sapwood 
and  heartwood.  Moreover,  the  properties  of  the  same  piece  of 
wood  may  vary  from  day  to  day  as  the  result  of  ordinary  change? 
in  the  amount  of  moisture  in  the  atmosphere.  It  is  obviously 
easy  to  measure  the  strength  of  a  specimen  that  has  once  been 
selected,  but  very  difficult  to  secure  the  specimen  if  it  is  to  stand 
for  the  species  as  a  whole. 

A  test  designed  to  measure  strength  or  any  other  property, 
includes  three  parts  or  operations :  (1)  A  specimen  that  will  repre- 
sent the  material  must  be  selected;  (2)  the  specimen  must  be 
prepared  for  the  test,  that  is,  it  must  be  reduced  to  exact  dimen- 
sions; (3)  the  prepared  specimen  must  be  tested  in  a  machine 
designed  for  that  purpose.  The  difficulty  is  encountered  under 
the  first  heading. 

The  physical  properties  of  woods  are  often  measured,  but 
comparatively  few  of  the  results  obtained  agree  closely  with  one 
another;  variations  of  as  much  as  one  hundred  per  cent,  are  not 
uncommon.  All  specimens  are  tested  in  practically  the  same 
manner  so  that  the  discrepancies  must  be  due  to  the  fact  that  the 
specimens  are  seldom  selected  and  prepared  upon  a  common  basis. 
Differences  which  existed  in  the  properties  of  several  specimens 
of  Eucalyptus  wood  are  shown  by  the  tables  on  pages  253  and  254. 

The  principal  points  upon  which  engineers  have  not  agreed 
when  selecting  and  preparing  test-specimens  of  wood  relate  to 
standards  for  moisture  and  sizes  of  test-specimens. 

(1)  STANDARDS  FOR  MOISTURE.— Wood-elements  become 
soft,  swollen  and  pliable  where  they  are  wet.     Seasoning  expels 
some   of    the   moisture  and    brings  a  larger  number  of  wood- 
elements  within  a  given  space.     The  wood  is  then  stronger  and 
more  rigid.     These  matters  may  cause  the  strength  of  wood  to 
vary  as  much  as  four  hundred  per  cent.     A  standard  is  there- 
fore  necessary.     In  tests  conducted  for  the  National   Forest 
Service,   Professors   Fernow  and  Johnson  adopted  twelve  per 
cent,  by  weight  of  dry  wood  as  their  standard.1 

(2)  SIZES    OF   TEST-SPECIMENS.— It  is  easier   to   select 
representative  samples  of  stones  and  metals  than  to  select  samples 
of  woods  in  which  conditions  with  regard  to  age,  grain,  moisture, 
imperfections  and  proportions  of  heartwood  are  all  approximately 
similar. 

1  See  index  for  "Moisture  in  Wood"  and  "Seasoning  in  Wood." 


PHYSICAL  PROPERTIES  OF  WOODS 


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PHYSICAL  PROPERTIES  OF  WOODS  255 

Large  Test-specimens. — It  is  hard  to  select  large  pieces  of 
wood  upon  a  common  basis.  Most  large  pieces  are  individual 
rather  than  representative  and  tests  of  such  pieces  yield  results 
for  the  pieces  thus  broken  rather  than  results  that  represent  the 
species  at  large.  On  the  other  hand,  tests  of  large  pieces  are 
useful  because  they  show  the  results  of  imperfections. 

Small  Test-specimens. — The  fact  that  small  pieces  are  abnor- 
mally perfect  causes  them  to  yield  results  that  are  larger  than 
those  observed  in  actual  practice.  But  such  pieces  possess  the 
advantage  that  it  is  easier  to  select  them  upon  a  common  basis. 
The  results  of  tests  upon  small  specimens  agree  more  nearly  with 
one  another  and  are  practical  in  that  they  make  comparisons 
possible. 

Large  and  Small  Test-specimens. — The  purpose  for  which  the 
test  is  to  be  made  should  be  considered.  If  the  examination  is 
to  be  exhaustive,  large  and  small  pieces  should  both  be  tested. 


The  differences  that,  exist  between  the  physical  properties  of 
woods  and  the  physical  properties  of  ordinary  inorganic  struc- 
tural materials,  may  be  epitomized  as  follows : 

1.  Stones  and  metals  possess  physical  and  chemical  properties,  while 
woods  possess  physical  and  chemical  properties  and  also  other  properties 
that  result  from  physiological  processes. 

2.  The  properties  that  result  from  physiological  processes  cause  woods 
to  vary.     Pieces  cut  from  the  same  tree  differ  from  one  another,  while 
the  same  piece  may  vary  from  day  to  day  as  water  is  absorbed  and  dis- 
pelled.    Changes  in  woods  are  caused  by  seasoning  and  the  application 
of  preservatives.     Stones  and  metals  are  much  more  homogeneous  and 
constant. 

3.  It  is  comparatively  easy  to  select  representative  samples  of  stones 
and  metals,  but  it  is  not  easy  for  the  average  experimenter  to  select 
samples  of  woods  upon  a  common  basis  as  to  moisture  and  imperfections. 

4.  Engineers  have  agreed  to  a  greater  extent  upon  specifications  for 
testing  stones  and  metals,  and  to  a  less  extent  upon  specifications  for 
testing  woods. 

5.  Stones  and  metals  are  often  tested  by  those  who  use  them.     Woods 
are  less  often  tested  by  those  who  use  them.     In  the  case  of  woods,  the 
results  of  tests  conducted  in  Government  or  other  laboratories  are  often 
preferred  when  such  figures  are  employed  at  all. 

6.  Tests  of  stones  and  metals  when  conducted  upon  a  scientific  basis, 
give  helpfully  practical  results.     The  coefficients  of  safety  are  here  com- 
paratively low  and  constant. 


256  ORGANIC  STRUCTURAL  MATERIALS 

7.  Tests  of  woods  when  conducted  upon  a  scientific  basis  do  not  give 
equally  practical  results.  The  coefficients  of  safety  are  high  and  vari- 
able. Results  obtained  in  this  way  are  not  satisfactory  criteria  of  the 
actual  working  strength  of  the  pieces.1 


Two  facts  are  emphasized:  One  is  that  the  basis  upon  which 
the  sample  is  selected  and  prepared  is  of  unusual  importance  in 
the  case  of  a  substance  as  variable  as  wood;  and  the  other  is 


FIG.  39. — Dorry  machine  for  making  abrasion  tests. 

that  all  figures  obtained  for  woods  should  be  used  with  the  very 
greatest  caution.  Such  figures  should  never,  under  any  con- 
sideration, be  used  with  the  confidence  that  is  warranted  in  con- 
nection with  figures  obtained  similarly  for  the  more  homogeneous 
stones  and  metals. 

The  tests  made  to  obtain  values  for  the  physical  properties  of 
woods  can  be  arranged  in  several  groups,  each  one  depending 

1  For  discussion  of  factors  of  safety  and  safe  working  stresses  for  structural 
timbers,  see  Report  of  Committee  on  Wooden  Bridges  and  Trestles,  American 
Railway  Engineering  Association,  Bulletin  No.  107. 


PHYSICAL  PROPERTIES  OF  WOODS  257 

primarily    upon   the   way   in    which   the   test-specimens    were 
selected.     These  groups  are  as  follows: 

1.  Many  experiments  have  been  performed  from  time  to  time 
that  have  not  been  characterized  by  any  particular  method  or 
principle  such  as  underlie  the  investigations  that  will  be  described 
in  the  succeeding  paragraphs.     Details  as  to  the  selection  of 
specimens  are  incompletely  given  or  are  entirely  lacking.     The 
botanical  accuracy  of  the  specimens  is  open  to  doubt  in  many 
cases.     Major  attention  was  given  to  the  manipulation  of  the 
specimens    in    the    testing    machines.     Properties    other    than 
strength  and  weight  were  seldom  noticed.     All  of  the  experiments 
that  are  not  alluded  to  in  the  descriptions  that  follow  are  included 
in  this  group. 

The  results  of  the  experiments  included  under  this  head  differ 
widely  from  one  another,  but  some  of  them  are  helpful  for  special 
reasons;  for  example,  Laslett  and  Rankin's  experiments  were 
performed  principally  upon  foreign  woods. 

2.  Experiments  were  conducted  for  the  Tenth  United  States 
Census,  by  Sharpless,  at  the  Watertown  Massachusetts  Arsenal. 
Botanical    accuracy  was   assured,   but  in    other   respects    the 
selection  of  specimens  was  not  guided  by  factors  that  would 
now  be  considered.     So  far  as  is  known,  most  of  the  specimens 
were  from  the  butts  of  trees.     Nothing  is  known  of  moisture 
conditions  save  that  specimens  were  carefully  seasoned.     About 
twelve  hundred  specimens,  representing  over  four  hundred  species, 
were  tested.    This  allowed  only  two  or  three  tests  for  each  species. 

The  series  is  valuable  because  it  includes  almost  all  American 
species,  and  the  results  arrived  at  are  often  quoted.  It  is  well  to 
note  that  part  of  the  results  of  these  experiments  were  originally 
reported  in  the  metric  system.  Coefficients  were  originally  com- 
puted in  kilograms  and  millimeters,  whereas  weights  were  given 
in  pounds.  This  has  led  to  some  confusion. 

These  experiments  are  characterized  as  follows: 

Botanical  accuracy  was  assured. 

Methods  of  selection  were  not  definitely  described. 

Moisture  conditions  were  not  standardized  as  far  as  known. 

Small  specimens  alone  were  tested. 

Few  tests  were  performed. 

A  large  number  of  species  was  covered. 


258  ORGANIC  STRUCTURAL  MATERIALS 

These  experiments  were  described  originally  in  Vol.  IX, 
Tenth  United  States  Census;  Executive  Document  No.  5,  Forty- 
eighth  Congress,  First  Session;  Sargent's  "Silva  of  North 
America"  and  "Catalogue  of  the  Jesup  Collection  of  Woods." 

3.  Some  experimenters,  while  admitting  the  difficulties  that 
have  been  noted,  prefer  to  test  large  specimens  because  they  are 
the  ones  employed  in  practice.     One  important  result  obtained 
by  such  experiments  is  the  determination  of  the  extent  to  which 
imperfections   lower   strength.     Experiments   conducted   under 
this  head  are  described  in  Professor  Lanza's  "  Applied  Mechanics  " 
and  in  publications  noted  in  the  succeeding  sections. 

4.  In  a  series  of  experiments  conducted  for  the  National  Forest 
Service,   then  called  the  United  States  Division  of  Forestry, 
Professors  Fernow  and  Johnson  acknowledged  the  difficulties  of 
selection  that  have  been  noted.     Test-specimens  were  selected 
upon  a  common  basis  as  to  age,  moisture,  proportions  of  heart- 
wood,  imperfections,  and  other  matters,  and  about  forty  thousand 
tests  were  made,  distributed  over  thirty-one  American  species. 
Both  large  and  small  test-specimens  were  employed. 

The  details  considered  and  the  methods  evolved  during  this 
study  were  of  such  a  nature  as  to  influence  all  subsequent  efforts. 
The  study  is  disappointing,  in  that  results  were  obtained  for  so 
few  species. 

The  series  is  characterized  as  follows : 

Botanical  accuracy  was  assured. 
Soil  and  forest  conditions  were  noticed. 
Test-specimens  were  from  representative  portions  of  trees. 
Representative  trees  were  selected. 

Moisture  conditions  were  standardized  at  12  per  cent,  of  the  dry 
weight  of  the  wood. 

Small  test-specimens  and  large  test-specimens  were  used. 

Studies  of  strength  and  weight  were  emphasized. 

Many  tests  were  made. 

A  small  number  of  species  was  covered. 

The  records  are  complete  and  reliable. 

These  experiments  were  originally  described  in  Circular  No.  15 
and  other  publications  of  the  National  Division  of  Forestry,  in 


PHYSICAL  PROPERTIES  OF  WOODS  259 

Professor  J.  B.  Johnson's  "Materials  of  Construction"  and  in 
Professor  Fernow's  "  Timber  Physics,"  Parts  1  and  2.1 

5.  A  series  of  experiments  begun  more  recently  (1902)  by  the 
National  Forest  Service,  is  distinct  from  the  one  referred  to  in  the 
preceding  articles  as  follows:  The  earlier  study  was  character- 
ized by  emphasis  laid  upon  strength  and  weight,  while  the  later 
study  is  characterized  by  attention  paid  to  other  properties  as 
well.  Physical  properties  are  studied,  but,  in  addition  to  these, 
there  are  investigations  of  technological  processes  such  as  kiln- 
drying  and  the  application  of  preservatives.  The  influences  of 
some  of  these  processes  and  materials  upon  physical  properties 
have  been  investigated. 

These  tests  may  be  grouped  as  follows:  (1)  Tests  of  life-sized 
pieces  or  market  products,  such  as  bridge  stringers,  railway  ties, 
wheel  spokes,  and  axe  handles,  intended  to  yield  results  upon 
which  grading  rules,  specifications,  and  coefficients  for  design 
can  be  based.  (2)  Tests  of  smaller  pieces  selected  upon  the  same 
basis  as  to  silvi-cultural  conditions,  age,  grain,  imperfections,  and 
moisture.  The  details  of  the  tests  are  varied.  The  influence  of 
speed  of  application  of  load,  temperature,  etc.,  is  noted.  All  the 
conditions  alluded  to  in  the  earlier  part  of  this  chapter  have  been 
provided  for  in  these  experiments,  which  are  second  to  none  in 
both  scientific  and  practical  importance. 

These  investigations,  organized  by  Professor  William  Ken- 
drick  Hatt,  have  been  described  in  the  "  Transactions  of  the 
American  Society  of  Civil  Engineers,"  Vol.  LI,  1903;  in  the 
"  Progress  Report  on  the  Strength  of  Structural  Timber"  (United 
States  Bureau  of  Forestry,  Circular  No.  32,  1904);  in  "  Instruc- 
tions to  Engineers  of  Timber  Tests,"  Hatt  (United  States  Forest 
Service,  Circular  No.  38,  1906);  in  the  "Second  Progress  Report 
on  the  Strength  of  Structural  Timber,"  Hatt  (United  States 
Forest  Service,  Circular  No.  115,  1907);  in  "Strength  Values  for 
Structural  Timbers,"  Cline  (United  States  Forest  Service,  Cir- 
cular No.  189);  and  elsewhere.2 

1  Publications  of  the  National  Forest  Service. 

2  See  also  report  of  the  Committee  on  Wooden  Bridges  and  Trestles  of 
The  American  Railway  Engineering  Association,  reprinted  in  Engineering 
News,   March  25,   1909,  and  referred  to  in  Engineering  News,  February 
22,  1912,  as  probably  the  best  compilation  of  safe  values  to  be  used  for 
unit  stresses  in  structural  timbers. 


260  ORGANIC  STRUCTURAL  MATERIALS 

Density  Test  for  Grading  Southern  Hard  Pine. — This  test,  which 
is  employed  to  grade  the  various  kinds  of  Southern  Hard  Pine 
timbers,  is  the  result  of  a  long  investigation  conducted  by  the 
United  States  Forest  Service  and  the  American  Society  for 
Testing  Materials.  The  experiments  showed  that  the  strength 
of  Southern  Hard  Pine  timbers  depends  less  upon  peculiarities 
due  to  species  than  upon  the  cellular  structure  of  individual 
pieces. 

Until  the  Density  Test  was  suggested  no  standard  existed  by 
which  the  quality  of  individual  timbers  could  be  determined 
accurately.  The  rule,  which  is  characterized  by  brevity  and 
simplicity,  is  as  follows:1 

DENSITY  RULE  FOR  GRADING  SOUTHERN  HARD  PINE 

"Dense  Southern  yellow  pine  shall  show  on  either  end  an  average  of 
at  least  six  annual  rings  per  inch  and  at  least  one-third  summer  wood, 
or  else  the  greater  number  of  the  rings  shall  show  at  least  one-third 
summer  wood,  all  as  measured  over  the  third,  fourth  and  fifth  inches 
on  a  radial  line  from  the  pith.  Wide-ringed  material  excluded  by  this 
rule  will  be  acceptable  provided  that  the  amount  of  summer  wood  as 
above  measured  shall  be  at  least  one-half. 

"The  contrast  in  color  between  summer  wood  and  spring  wood  shall 
be  sharp,  and  the  summer  wood  shall  be  dark  in  color,  except  in  pieces 
having  considerably  above  the  minimum  requirement  for  summer  wood. 

"In  cases  where  timbers  do  not  contain  the  pith  and  it  is  impossible 
to  locate  it  with  any  degree  of  accuracy,  the  same  inspection  shall  be 
made  over  3  inches  on  an  approximate  radial  line  beginning  at  the  edge 
nearest  the  pith  in  timbers  over  3  inches  in  thickness,  and  on  the  second 
inch  (on  the  piece)  nearest  to  the  pith  in  timbers  3  inches  or  less  in 
thickness. 

"In  dimension  material  containing  the  pith,  but  not  a  5-inch  radial 
line,  which  is  less  than  2  by  8  inches  in  section  or  less  than  8  inches  in 
width,  that  does  not  show  over  16  square  inches  on  the  cross-section,  the 
inspection  shall  apply  to  the  second  inch  from  the  pith.  In  larger  mate- 
rial that  does  not  show  a  5-inch  radial  line  the  inspection  shall  apply  to 
the  3  inches  farthest  from  the  pith. 

"Sound  Southern  yellow  pine  shall  include  pieces  of  Southern  pine 
without  any  ring  or  summer-wood  requirement." 

Von  Schrenk  comments  upon  these  rules  as  follows: 

"While  the  new  rule  may  at  first  sight  appear  to  be  a  somewhat 
radical  departure  from  past  standards,  a  careful  study  will  show  that 

^'Yellow-Pine  Timber  Graded  Without  Guesswork,"  von  Schrenk 
(Engineering  News,  February  24,  1916). 


PHYSICAL  PROPERTIES  OF  WOODS  261 

such  is  not  really  the  case.  The  Density  Rule,  when  applied  to  a  mixed 
lot  of  the  various  Southern  pine  timbers  of  the  several  botanical  species, 
will  include  most  of  the  pieces  of  the  true  botanical  longleaf  pine  in  the 
grade  hereafter  to  be  known  as  " Dense  Pine;"  a  smaller  percentage  of 
the  denser  pieces  of  loblolly,  Cuban  and  shortleaf  pine  also  will  fall 
within  the  dense  grade;  and  on  the  other  hand,  a  small  percentage  of 
the  more  rapid-growing  pieces  of  longleaf  will  be  excluded,  as  will  also 
a  great  majority  of  pieces  of  loblolly,  Cuban  and  shortleaf. 

"It  should  be  clearly  understood  that  the  classes  "Dense  Pine"  and 
the  less  desirable  "Sound  Pine"  refer  specifically  to  quality  of  density 
when  considered  from  the  structural  or  strength  standpoint  and  that 
they  replace  the  botanical  terms  hitherto  used — longleaf,  shortleaf,  lob- 
lolly, etc. 

"It  should  also  be  clearly  understood  that  the  usual  specifications 
as  to  the  percentage  of  heart  and  sap  are  in  no  way  changed.  In  other 
words,  where  timber  for  long  service  is  demanded,  together  with  high 
strength  qualities,  Dense  Pine  should  be  specified  with  a  minimum 
amount  of  sapwood,  or  what  is  known  as  heart  timber. 

"A  feature  of  the  new  rule  that  particularly  recommends  it  is  that  it 
is  easy  of  application.  For  the  first  time  there  is  available  for  classifying 
structural  timbers  a  rule  which  is  based  on  actual  measurement  and 
which  has  nothing  to  do  with  catch- judgment  or  feeling.  Numerous 
diagrams  and  illustrations  in  the  Southern  Pine  Association's  density 
rule  book  show  how  simple  is  the  method  and  how  effectually  disagree- 
ments are  eliminated." 

THE  WEIGHTS  AND  MODULI  THAT  APPEAR  IN  THIS 
BOOK  ARE: 

First. — Those  derived  from  experiments  conducted  by  the  National 
Forest  Service  and  placed  in  the  "fourth  group"  explained  above. 
These  figures,  as  far  as  they  exist,  occupy  the  leading  spaces  in 
the  tabulated  descriptions  of  species  under  the  titles  "Weight," 
"Modulus  of  Elasticity,"  and  "Modulus  of  Rupture."  The  spaces 
set  apart  for  these  figures  are  left  vacant  for  other  insertions  where 
results  under  this  group  have  not  been  reported. 

Second. — Those  derived  from  experiments  conducted  at  the 
Watertown  Arsenal  by  the  Tenth  United  States  Census  and  placed 
in  the  "second  group"  explained  above.  These  figures  appear  in 
the  spaces  that  follow  those  set  apart  for  the  Forest  Service  figures 
or  their  equivalents.1 

All  coefficients  are  in  pounds  per  square  inch;  fractions  of 
pounds  in  weight  and  the  lower  figures  in  coefficients  have  been 
omitted  as  superfluous. 

1  Authorities  responsible  for  figures  other  than  those  mentioned  above 
are  given  in  connection  with  the  figures  employed. 


262  ORGANIC  STRUCTURAL  MATERIALS 

INFLUENCE  OF  MOISTURE,  ANTISEPTICS,  AND  HEAT  UPON  THE 
PHYSICAL  PROPERTIES  OF  WOODS 

MOISTURE  IN  WOOD.— Moisture  exerts  a  very  real  effect 
upon  the  physical  properties  of  wood.  Many  of  the  variations 
so  noticeable  in  these  properties  are  due  to  this  cause.  Moisture 
also  acts  upon  woods  in  other  ways;  for  example,  woods  suffer 
from  micro-organisms  that  are  assisted  in  their  life  and  growth 
by  the  presence  of  moisture. 

It  is  convenient  to  distinguish  between  the  kinds  of  moisture 
that  may  be  present  within  woods.  The  moisture  may  be  sap, 
introduced  while  the  tree  was  alive.  Or,  the  moisture  may  have 
been  introduced  later  after  the  tree  was  cut  down,  as  when 
finished  timbers  are  exposed  to  the  weather.  -  Other  moisture 
may  be  impure;  but  sap,  a  vital  fluid  necessary  to  the  life  of  trees, 
contains  preparations  that  are  of  an  organic  putrefactive  nature; 
and  these,  more  than  other  impurities,  seem  to  attract  micro- 
organisms, or  else  assist  their  progress  after  they  have  once 
entered  the  wood. 

The  quantity  of  the  moisture  and  its  distribution  are  both 
important. 

Quantity  of  Moisture. — One-half  of  the  weight  of  live  sapwood 
may  be  water.  There  is  less  water  in  heartwood  than  in  sap- 
wood,  and  more  in  young  and  vigorous  trees  than  in  those  that 
are  older  and  less  healthy.  All  trees  contain  more  sap  at  some 
seasons  of  the  year  than  at  others;  and  all  woods,  even  when 
well  seasoned  and  apparently  dry,  contain  some  water.  The 
porous  structure  of  clean  wood  permits  water  to  pass  in  and  out, 
so  that  in  the  same  piece,  the  quantity  of  water  may  vary  from 
day  to  day. 


Influence  of  Season  of  Cutting. — The  influence  which  the  season  of 
cutting  exerts  upon  wood  may  be  noted  in  this  connection.  The  usual 
preference  exhibited  for  winter  felled  timber  has  several  causes.  (1)  It 
is  thought  by  many  that  the  quantity  of  moisture  in  a  tree  is  so  much 
less  during  the  winter  that  the  quality  of  the  wood  is  affected.  (2) 
Others  prefer  the  winter  for  felling  because  fungi  are  then  less  active 
and  there  is  less  danger  of  infection  before  the  log  can  be  cut  up  in  the 
mill.  (3)  Yet  others  regard  the  quality  of  the  wood  itself  as  better 
during  the  winter  season.  (4)  In  the  North,  lumbermen  prefer  the 


INFLUENCE  OF  MOISTURE  ON  WOODS 


263 


winter  season  for  cutting  because  transportation  problems  in  the  forest 
are  then  more  easily  met.  These  points  will  be  considered  separately : 

First,  there  is  fully  as  much  sap  in  a  tree  during  the  winter  as  during 
summer.     Its  composition  may  vary,  but  its  total  amount  is,  if  anything, 
greater  during  the  winter.1     Second,  it  is  true  that  fungi  are  less  active 
during  the  winter  season  and  that  there  is 
less  danger  of  freshly  cut  wood  becoming 
infected   and   consequently   weakened  at 
that  time.     Third,  with  the  exception  of 
the  outer  sapwood,  no  real  difference  exists 
in  the  quality  of  the  trunk   during  the 
winter  and  the    summer.     Fourth,    this 
point   is   one   of    convenience    and    has 
nothing  to   do   with  the  quality  of   the 
wood. 

Of  the  above  points  the  second  only 
need  be  considered  as  a  factor  influencing 
the  quality  of  wood.  As  a  matter  of  fact 
if  summer  felled  logs  and  winter  felled 
logs  could  both  be  immediately  cut  up  into 

lumber  as  soon  as  they  were  felled,  and  if  the  wood  in  each  case  could 
then  ^be  promptly  and  equally  seasoned  by  the  same  process  the  two 
kinds  could  not  be  distinguished  from  one  another. 


FIG.   40. — Defects  due  to 
unequal  shrinkage.2 


Distribution  of  Moisture. — The  practical  importance  of  this 
subject  will  be  appreciated  when  it  is  remembered  that  the  prin- 
cipal difficulty  encountered  by  those  who  season  woods  arises 
from  attempts  to  expel  moisture  evenly  from  all  parts  of  a  piece 
in  which  it  does  not  exist  evenly. 

Distribution  may  be  studied  from  the  standpoint  of  the  entire 
piece,  and  it  may  be  studied  locally  as  it  relates  to  the  wood- 
elements.  The  distribution  throughout  the  entire  piece  is  such 
that  there  is  more  water  in  the  sapwood  than  in  the  heart.  Mois- 
ture is  distributed  throughout  the  wood-elements,  so  that  some 
of  it  occupies  the  cavities  in  the  wood-elements  and  some  satur- 
ates the  walls  of  the  wood-elements. 


1  "Sap  in  Relation  to  the  Properties  of  Wood,"  Record  (Proc.  American 
Wood  Preservers'  Association,  Baltimore,  Md.,  1913,  pp.  160-166). 

2  Acknowledgments  to  United  States  Forestry  Division,  Roth,  Bulletin 
No.  10,  pp.  33  and  35. 


264  ORGANIC  STRUCTURAL  MATERIALS 

Influence  of  Moisture. — There  are  three  ways  in  which  mois- 
ture influences  woods:  (1)  moisture  causes  weakness  and  other- 
wise affects  the  physical  properties  of  woods;  (2)  moisture  influ- 
ences distortion;  and  (3)  moisture  is  a  factor  in  decay. 

INFLUENCE  OF  MOISTURE  ON  PHYSICAL  PROPERTIES 
OF  WOODS. — Wood-elements  are  swollen  and  pliable  when 
they  are  wet.  Seasoning  expels  moisture  and  brings  more  of  them 
within  a  given  space.  The  woods  are  then  drier  and  stronger. 
Seasoning  may  increase  strength  as  much  as  four  hundred  per 
cent.;  and  comparatively  weak  wood,  such  as  pines,  may  be 
thus  rendered  stronger  than  better  woods,  such  as  oaks,  that 
have  not  been  seasoned. 

The  influence  of  moisture  upon  the  strength  of  wood  has  been 
summarized  by  Tiemann:1 

"As  the  moisture  of  a  piece  of  wood  is  reduced  by  drying,  the  strength 
of  the  wood  increases,  and  as  moisture  is  re-absorbed,  the  strength,  up 
to  a  certain  limit,  is  again  reduced.  So  great,  indeed,  is  the  effect  of 
moisture,  that  under  ordinary  conditions  it  outweighs  all  other  causes 
that  affect  strength,  with  the  exception,  perhaps,  of  decided  imperfec- 
tions in  the  wood." 

An  .exception  must  be  noted.  It  is  hard  to  dry  a  large  timber 
that  is  full  of  knots  and  other  irregularities  without  some  injury 
to  the  piece  as  a  whole;  and  this  injury  may  offset  much  of  the 
improvement  that  takes  place  otherwise  through  seasoning.  To 
prevent  decay,  all  wood  should  be  dry,  and  all  wood-elements 
and  most  timbers  are  stronger  when  they  are  dry;  but  the  net 
strength  of  a  very  imperfect  piece  may  not  be  always  greatly 
increased  by  drying. 

The  Influence  of  Moisture  upon  Distortion. — The  changes  that 
take  place  in  the  form  of  a  piece  of  wood  are  due  to  the  discharge 
of  water  from  the  wood-elements.  The  fact  that  moisture  is  not 
distributed  evenly  throughout  the  wood,  and  the  further  fact 
that  wood-elements  vary  in  their  character  and  arrangement  are 
important  in  this  connection. 

When  a  wood-element  shrinks  the  principal  change  takes  place 
in  its  thickness,  and  the  least  change  takes  place  in  the  direction 
of  its  length;  the  length  shrinkage  of  a  plank  can  usually  be  prac- 
tically disregarded.  Wood-elements  near  the  surface  of  a  log 

1  "Effect  of  Moisture  Upon  the  Strength  and  Stiffness  of  Wood,"  Tiemann 
(United  States  Forest  Service,  Bulletin  No.  70). 


PHYSICAL  PROPERTIES  OF  WOODS 


265 


contain  more  moisture  than  those  within;  and  the  sides  of  planks 
exposed  to  the  weather  may  shrink  differently  than  those  pro- 
tected. 

Horizontal  wood-elements  usually  shrink  differently  from  the 
vertical  wood-elements  that  are  bound 
together  by  them.  Severe  strains  at  right 
angles  to  one  another  are  then  developed 
and  the  separations  that  take  place  are 
known  as  checks.  Most  needle-leaf  woods 
shrink  evenly,  but  it  is  often  harder  to  expel 
moisture  from  broadleaf  woods,  such  as  oaks, 
that  are  characterized  by  complex  fiber 
arrangements  without  some  injury. 

Influence  of  Moisture  upon  Decay. — Decay 
is  due  to  the  action  of  certain  micro-organisms 
that  require  moisture  for  their  development, 
and  that  cannot  live  when  it  is  absent.  Decay 

is  not  inherent  in  woods ; 

dry  woods  do  not  decay. 

Decay  m  a  y  p  r  o  c  e  e  d      Fw   4i;_Result  of 

when    the   moisture    is  unequal  shrinkage. 

rmrA    Hnt    ear*     a«    Hie     The  formation   of 
pure,  out  sap,  as  ais-  checks  i 

tinct  from  pure  water, 

contains  compounds  that  attract  or  that 

add  to  the  activity  of  the  forms  that  cause 

decay.2 

Influence  of  Antiseptics  and  Preservative 
Treatment  Upon  the  Physical  Properties 
of  Woods. — The  phj^sical  properties  of 
woods  may  be  influenced  by  (1)  the  anti- 
septic, and  by  (2)  the  process  employed  to 
introduce  the  antiseptic. 

The  effect  of  creosote  upon  the  physical 
properties  of  woods  is  negligible  or  bene- 
ficial. But  zinc  chloride  and  some  other  preservatives  designed 
to  benefit  woods  in  some  ways  may  injure  them  in  others.  Not 
only  can  a  concentrated  solution  of  zinc  chloride  injure  tissues 
with  which  it  comes  into  contact,  but  the  timber  as  a  whole  may 

1  Acknowledgments  to  Roth   (United  States  Division  Forestry  Bulletin 
No.  10,  p.  34). 

1  See  index,  " Fungi,"  "Fungus  Diseases  of  Woods,"  etc.,  etc. 


FIG.  42. — The  rela- 
tion of  horizontal 
wood-elements  to  verti- 
cal wood-elements.  6, 
a  are  vertical  wood-ele- 
ments, while  c,  d  are 
cells  of  a  pith-ray.1 


266  ORGANIC  STRUCTURAL  MATERIALS 

be  weakened  by  the  addition  of  water.  Otherwise,  experiments 
indicate  that  the  presence  of  zinc  chloride  will  not  weaken  woods 
subjected  to  static  loading,  although  the  indications  are  that 
pieces  that  have  been  subjected  to  zinc  chloride  treatment  become 
brittle  under  impact.1 

As  distinct  from  the  preservative,  a  process  may  be  harmful 
whenever  excessively  high  temperatures  are  employed.  If  an 
appropriate  process  is  selected,  and  if  proper  care  is  observed 
while  it  is  being  applied,  the  wood  will  not  suffer. 

Influence  of  Heat  upon  Physical  Properties.2 — Dry  heat  must 
be  distinguished  from  wet  heat.  Dry  heat  much  in  excess  of 
212  degrees  expels  some  of  the  volatile  products  of  the  wood  and 
the  wood  then  becomes  correspondingly  weak  and  brittle.  The 
equivalent  of  moist  heat  is  not  known.  Up  to  a  certain  point 
high  heat,  either  in  steam  or  in  dry  air,  produced  the  following 
results  upon  wood: 

"(1)  It  permanently  reduces  the  moisture  content  below  that  of 
ordinary  air-dried  wood  when  again  exposed  to  the  air,  at  the  same  time 
rendering  it  less  hygroscopic,  so  that  it  is  less  susceptible  to  changes  in 
the  humidity  of  the  air;  (2)  the  moisture  condition  of  the  fiber-saturation 
point  is  changed,  being  reduced  by  high  temperatures  with  dry  air  or 
superheated  steam;  (3)  the  strength  of  the  wood  is  increased,  except  in 
the  resoaked  condition." 


Woods  deteriorate,  or  fail,  from  use,  exposure,  age,  decay,  fire, 
marine  life,  and  land  life;  and  they  are  defended  more  or  less 
successfully  by  seasoning,  internal  treatment,  and  external  treat- 
ment. These  subjects  will  be  treated  separately  in  the  chapters 
that  follow. 

1  "Experiments  on  the  Strength  of  Treated  Timber,"  Hatt  (United  States 
Forest  Service,  Circular  No.  39,  p.  21);  "Crosstie  Forms  and  Rail  Fastenings 
with  Special  Reference  to  Treated  Timbers,"  von  Schrenk  (United  States 
Bureau  of  Forestry,  Bulletin  No.  50);  "A  Primer  of  Wood  Preservation," 
Sherfesee  (United  States  Forest  Service,  Circular  No.  139,  p.  9);  see  also 
chapter  entitled  "Preservatives  Applied  within  Woods,"  etc. 

2  See  index,  "Failure  of  Wood  Because  of  Fire." 


CHAPTER  X 

FAILURE  OF  WOOD  BECAUSE  OF  USE,  EXPOSURE,  AGE,  AND 

DECAY 

The  changes  that  take  place  as  a  result  of  use,  exposure,  and 
age,  are  distinct  from  those  that  take  place  as  a  result  of  disease. 
Changes  due  to  the  former  causes  are  of  a  mechanical  nature;  the 
wood-elements  remain  healthy  but  they  separate  more  easily 
from  one  another.  The  changes  due  to  decay  are  of  a  chemical 
nature;  disease  causes  wood  to  break  up  into  other  compounds. 

FAILURE  DUE  TO  USE. — The  mechanical  deterioration  of 
wood  is  influenced  by  the  way  in  which  it  is  used.  Flooring  is 
worn  by  abrasion.  The  life  of  a  railway  tie  may  be  measured,  by 
the  speed,  weight,  and  volume  of  traffic  that  passes  on  the  rails 
above.  Ability  to  hold  fastenings  is  a  factor  in  the  life  of  wood 
when  in  some  positions.  Thus  wood  may  wear  out  before  it 
rots.  Deterioration  due  to  use  is  opposed  by  physical  proper- 
ties such  as  strength,  hardness,  rigidity,  and  weight. 

FAILURE  DUE  TO  EXPOSURE. — Woods  may  deteriorate  as 
the  result  of  simple  exposure  to  the  weather.  Expansion  and 
contraction  due  to  extremes  of  temperature  and  the  presence  or 
absence  of  water  cause  wood-elements  to  loosen  from  one  another. 
Deterioration  takes  place  more  gradually  when  woods  are  pro- 
tected from  the  weather.  Wooden  roof-trusses  in  European 
churches  have  remained  good  during  many  centuries. 

FAILURE  DUE  TO  AGE.— Woods  " age"  much  more  rapidly 
when  out  of  doors.  Old  wood  becomes  brittle  and  is  then  known 
as  "brashwood."  In  a  living  tree  age  seldom  acts  alone,  but,  by 
lowering  the  vitality  of  the  tree,  makes  it  possible  for  disease  to 
enter  where  resistance  has  been  overcome.  There  is  probably  no 
such  thing  as  the  natural  death  of  a  tree  in  the  forest  and  it  is 
equally  true  that  woods  seldom  fail  in  construction,  simply 
because  they  are  old.  The  vitality,  soundness  or  resistance  of 
a  piece  of  wood  may  be  roughly  estimated  by  twisting  a  shaving 
of  it  between  the  fingers. 

267 


268  ORGANIC  STRUCTURAL  MATERIALS 

FAILURE  DUE  TO  DECAY.  FUNGOUS  DISEASES.— Trees 
in  the  forests,  and  woods  waiting  to  be  used,  or  already  in  con- 
structions, are  susceptible  to  diseases  that  cause  losses  so  serious 
as  to  constitute  one  of  the  greatest  drains  upon  the  timber 
resources  of  the  world. 

All  wood,  whether  employed  in  railroad  ties,  telegraph  poles, 
bridge,  mine  or  house  timbers,  are  susceptible  to  the  same  or 
similar  diseases.  Wooden  warships  once  suffered  more  from  them 
than  from  the  guns  of  the  enemy.  It  is  said  that  wooden  ships 
have  failed  after  seven  or  eight  years  of  service.  Selection,  seas- 
oning, and  the  attention  paid  to  protection  makes  it  possible  for 
woods  to  last  longer  at  the  present  time;  yet  even  now  woods 
exposed  to  the  weather  endure  for  a  comparatively  short  time, 
while  the  premature  failure  of  beams  in  protected  places  is  not 
uncommon. 

Many  names  refer  to  practically  the  same  causes  of  deteriora- 
tion in  wood.  Wet-rot,  dry-rot,  disease,  decay,  mildew,  soft-rot, 
canker,  bluing,  rust,  bot,  dote,  mould,  and  other  terms  are  thus 
employed.  The  results  indicated  by  all  of  these  names  are  due 
to  the  presence  of  bacteria  or  fungi. 

Fungi. — These  non-seedbearing  plants  differ  from  ferns  and 
mosses,  which  are  also  non-seedbearing  plants,  in  that  the  latter 
require  light  and  contain  the  green  substance  chlorophyll  which 
serves  in  the  preparation  of  plant  food;  whereas  the  former,  that 
is  fungi,  are  without  chlorophyll  and  do  not  require  light.  Fungi 
cannot  draw  their  food  from  air  and  soil  like  ordinary  plants  and 
must  therefore  attach  themselves  to  appropriate  substances  from 
which  they  can  draw  their  food.  Fungi  are  destructive  rather 
than  constructive  and  in  this  respect  resemble  animals  rather 
than  plants. 


REFERENCES. — "Outlines  of  Botany,"  Leavitt;  "Fungous  Diseases  of 
Plants,"  Duggar;  "Diseases  of  Economic  Plants,"  Stevens  and  Hall; 
"Flowerless  Plants,"  Bennett  (Gurney  &  Jackson,  London);  "Fungous 
Diseases  of  our  Forest  Trees,"  Halstead  (3rd  Annual  Report  Penn.  Dept. 
of  Agriculture) ;  " Diseases  of  Trees,"  Hartig;  "Diseases  of  Plants  Induced  by 
Cryptogamic  Parasites,"  Tubeuf  and  Smith;  "Studies  of  Some  Shade  Tree 
and  Timber  Destroying  Fungi,"  Atkinson  (Cornell  Exper.  Sta.  Bulletin 
No.  193);  Bulletins  American  Railway  Engineering  Association;  "The  Dis- 
covery of  Cancer  in  Plants"  (The  National  Geographic  Magazine,  Vol. 
XXIV,  No.  1,  1913);  etc. 


PLATE  V.     FUNGOUS  DISEASES  OF  WOOD 


FIG.  A.  FIG.  B. 

FIG.  A. — Fruiting  Bodies  of  Fungus  (Fomes  fomentarius)  (a). 
FIG.  B. — Fruiting  Bodies  of  Fungus  (Daedalea  quercina)  (6). 


FIG.  C. 

FIG.  C. — Fruiting   Body   of   Fungus    (Lentinus  lepidus)   on   Red   Fir 
Railway  Tie  (c). 

(a)  and  (6)  From  "Diseases  of  Deciduous  Forest  Trees,"  von  Schrenk  and  Spauldirig 
(United  States  Bureau  of  Plant  Industry,  Bulletin  149).  (c)  From  "  Seasoning  of  Timber," 
von  Schrenk  (United  States  Bureau  of  Forestry,  Bulletin  41). 

(Facing  page  268.) 


USE  AGE  AND  DECAY  OF  WOODS 


269 


Plant  Life  Has  Been  Divided  in  Many  Ways. — The  Linnsean  classi- 
fication separates  all  plants  into  Phanerogams,  or  seed-bearing  plants, 
and  Cryptogams,  or  non-seedbearing  plants.  The  Cryptogams  are 
again  divided  into  one  part,  sometimes  called  the  higher,  which  includes 
the  ferns  and  mosses;  and  another  part,  sometimes  called  the  lower, 
which  includes  the  algae,  lichens,  and  fungi. 

The  fungi  are  divided  into  saprophytes  and  parasites  according  as 
they  derive  food  from  dead  or  living  tissues.  Some  species  are  capable 
of  existing  as  both  saprophytes  and  parasites  and  for  this  reason  some 
authorities  (see  Tubeuf  and  Smith,  p.  3)  separate  fungi  into  true  and 
hemi-saprophytes  and  true  and  hemi -parasites.  There  are  sub-divisions 
in  each  case. 


A  piece  of  mouldy  bread  may 
be  studied  in  this  connection  with 
profit.  Such  bread  first  emits  a 
characteristic  odor,  then  becomes 
discolored,  and  is  eventually  de- 
stroyed. Minute  threads  of  the 
" mould"  penetrate  throughout 
the  mass  and  their  extremities 
eventually  appear  upon  the  sur- 
face of  the  bread  as  a  delicate  felt 
or  fur.  These  extremities  finally 
swell,  burst,  and  liberate  countless 
spores,  some  of  which  find  a  con- 
genial substratum,  germinate,  and 
produce  similar  results. 

The  swollen  ends  of  the  ex- 
tremities are  the  "fruiting  bodies" 
of  the  fungi  within  the  bread.  In 
the  same  way  the  toadstool-like  FIG.  43.— Mycelial  threads  of 
growths  seen  on  rotting;  trees  or  wood-destroying  fungus  (Nectria 
°.  ,  ,  ((f  ...  ,  ,.  ,,  cinnabarina)  in  maple  wood.1 

timbers  are  the     fruiting  bodies 

of  fungi  that  have  entered  such  trees  or  timbers.  Fruiting 
bodies  are  not  always  easily  evident,  and  those  of  some  fungi 
are  quite  obscure.  An  individual  fungous  thread  or  filament  is 
called  a  "hypha,"  while  masses  of  the  threads  or  "hyphse"  form 
what  is  known  as  "mycelium."  Bread,  wood,  or  other  sub- 


1  Acknowledgments  to  Roth  (United  States  Division  of  Forestry,  Bulletin 
No.  10). 


270  ORGANIC  STRUCTURAL  MATERIALS 

stances  that  have  become  infected  are  the  "hosts"1  of  the  fungi 
that  have  gained  entrance  to  them. 

Fungi  attack  woods  through  the  action  of  solvents  called 
"enzymes,"  some  of  which  dissolve  cellulose,  while  others  dis- 
solve lignin,  starches,  sugars,  and  other  compounds.  The  re- 
moval of  any  one  of  these  constituents  from  the  wood  results, 
ultimately,  in  the  total  destruction  of  the  usefulness  of  the  wood. 
The  general  form  of  the  diseased  piece  may  be  retained  but  its 
properties  have  been  affected.  Some  of  these  wood  residues  are 
comparatively  dry  and  brittle  while  others  are  moist,  soft,  and 
sponge-like. 

Some  fungi  attack  live  trees.  Others  attack  dead  trees, 
and  yet  others  attack  woods  employed  in  construction.  Some 
kinds  of  fungi  prefer  conifers  and  others  broadleaf  trees.  Bark, 
heartwood,  and  sapwood  all  have  their  enemies.  Some  fungi 
attack  many  species  of  trees  or  woods,  while  others  attack  only 
one  or  two  species. 

Fungi  are  very  numerous.  Many  thousands  of  species  are 
in  existence.  The  subject  is  not  a  simple  one;  and  the  majority, 
who  are  not  experts  in  this  subject,  find  it  more  helpful  to  con- 
sider the  Jew  conditions  under  which  all  fungi  act  than  to  acquaint 
themselves,  with  the  idea  of  identifying  all  of  the  many  forms  that 
cause  the  failures  so  constantly  observed.2 

Conditions  Under  Which  All  Fungi  Act. — All  fungi  require 
moderate  quantities  of  heat,  air,  and  moisture  for  their  develop- 
ment. They  do  not  do  well  when  excessive  quantities  of  these 
agencies  are  present;  nor  do  they  do  well  when  the  said  agencies 
are  completely  absent. 

1.  Influence  of  Heat  upon  Fungi. — Growth  is  retarded  and 
fungi  are  sometimes  completely  killed  by  high  heat,  that  is  by 
temperatures  much  beyond  one  hundred  and  seventy  degrees. 
Many  fungi  are  killed  by  the  process  of  kiln-drying,  but  some  are 
rendered  inert  by  this  process  for  the  time  being  only.  The 
growth  of  fungi  is  also  retarded  by  cold,  that  is  by  temperatures 
much  below  thirty-five  degrees.3  Fungi  are  not  killed  by  any 

1  This  term  is  usually  restricted  to  the  living  organism  upon  which  a 
parasite  grows.     Saprophytes  grow  upon  a  "substratum." 

2  Fungi  do  not  confine  themselves  to  plants.     " Ringworm"  as  seen  in 
man  is  due  to  a  fungus  parasite  (Trichophyton  tonsurans). 

3  These  temperatures  are  approximate.     It  is  not  necessary  to  go  below 
the  freezing  point  to  retard  the  growth  of  fungi. 


USE  AGE  AND  DECAY  OF  WOODS          271 

degree  of  natural  cold,  no  matter  how  extreme,  but  their  activities 
cease,  or  are  restricted,  while  such  low  temperatures  continue. 

2.  Influence  of  Air  upon  Fungi. — The  activity  of  fungi  is  more 
or  less  opposed  by  an  abundance  of  pure  air  on  the  one  hand, 
and  by  vacuum  on  the  other.     A  moderate  amount  of  air  is 
necessary  for  their  growth. 

3.  Influence  of  Moisture  upon  Fungi. — Wood  will  not  decay 
while  it  is  quite  dry;  neither  will  it  decay  as  long  as  it  remains 
saturated  with  water. 

These  facts  explain  why  woods  last  better  in  cold  climates  and 
on  well-drained  hills,  and  why  decay  goes  forward  more  rapidly  in 
warm,  moist  climates,  and  in  mines.  A  railway  tie  fails  sooner 
than  a  beam  that  is  raised  up  from  the  ground  because  the  "  med- 
ium" conditions  of  heat,  air,  and  moisture  are  more  nearly  se- 
cured in  positions  where  ties  are  employed. 

Fungous  diseases  may  be  considered  as  they  attack  trees  in 
the  forest,  and  as  they  attack  woods  ready  for,  or  already  in, 
construction. 

Fungous  Diseases  of  Trees. — These  diseases  are  here  described 
for  the  sake  of  completeness,  and  because  some  of  them  produce 
results  that  are  evident  in  merchantable  lumber.  Some  of  the 
fungous  diseases  that  attack  living  trees  are  similar  to  the  fungous 
diseases  that  attack  woods  in  constructions. 

Trees  become  infected  through  wounds  such  as  the  borings  of 
insects  and  injuries  caused  by  falling  limbs  and  by  pruning. 
There  is  sometimes  an  intimate  connection  between  the  attacks 
of  insects  and  those, of  fungi.  Some  insects  transfer  the  micro- 
organisms to  trees  mechanically.  Sap  as  distinct  from  pure 
water  is  an  important  agent  in  the  growth  of  disease  that  has 
once  entered  the  tree. 

The  health  of  a  tree  is  important.  Good  health  increases 
resistance  to  disease,  which  resistance  is  less  where  health  is  low- 
ered, as  it  may  be  by  poor  soil,  by  lack  of  light,  and  by  the  attacks 
of  insects.  Old  trees  succumb  more  easily  than  younger  ones, 
but  there  is  probably  no  such  thing  as  the  natural  death  of  a 

See  also  " Diseases  of  Trees,"  Hartig;  "Diseases  of  Plants  Induced  by 
Cryptogamic  Parasites,"  Tubeuf  and  Smith;  "Disease  of  Taxodium  known 
as  Peckiness,"  von  Schrenk  (Contribution  14,  Shaw  School  of  Botany); 
"Fungus  Diseases  of  Forest  Trees,"  von  Schrenk  (United  States  Depart- 
ment of  Agriculture  Year  Book  1900);  "Diseases  of  Deciduous  Forest 
Trees,"  von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin 
No.  149  which  also  contains  extensive  bibliography);  etc. 


272 


ORGANIC  STRUCTURAL  MATERIALS 


tree.  To  preserve  health,  some  trees  protect  the  raw  surfaces  of 
wounds  with  their  own  gums  or  resins.  Intentional  wounds, 
such  as  those  caused  by  pruning,  should  be  coated  with  tar  or  paint. 

The  fungi  that  attack  trees  may  be  divided  as  they  attack  the 
foliage,  the  roots,  or  the  trunks  of  the  trees. 

Diseases  of  Foliage. — Leaves  that  have  been  attacked  by  spot, 
mildew,  or  rust,  cannot  adequately  perform  their  duties  and  the 
preparation  of  wood  is  correspondingly  interrupted.  The  foliage 
of  the  Soft  Maple  (Acer  saccharinum)  is  thus  subject  to  attack 
by  a  fungus  called  Phyllosticta  acericola.  Chestnut  foliage  is 
similarly  victimized  by  the  fungus  Marsonia  ochroleuca,  and  other 
fungi  are  associated  with  other  trees. 


FIG.  44. — Section  of  wood  cut  from  cypress  after  attack  by  wood-destroying 
fungus  (Dcedalea  vorax) . 

Diseases  of  Roots. — Certain  fungi  attack  the  roots  of  trees. 
For  example,  the  fungus  known  as  the  southern  root  rot  (Ozonium 
omnivorum)  attacks  the  roots  of  oaks  and  elms,  and  also  those 
of  some  smaller  plants  as  cotton.  When  the  roots  of  trees  are 
diseased,  the  wood  making  in  the  trunk  is  correspondingly  re- 
tarded. Hartig  states  that  barren  places  in  forests  are  often 
caused  by  root  fungi. 

Diseases  of  Trunks — The  trunks  of  live  trees  have  many 
enemies.  Cypress  and  Incense  Cedar  are  sometimes  attacked 
by  the  fungus  Dcedalea  vorax  that  causes  peculiar  cavities  in  the 
wood.  The  Bull  Pine  (Pinus  ponderosa)  is  subject  to  attack  by 
the  fungus  Ceratostomella  pilifera  that  causes  the  wood  to  become 
blue.  The  bark  of  the  chestnut  is  subject  to  the  bark  disease 
(Disporthe  parasitica  or  Endothia  gyrosa  var  parasitica),  which 


USE  AGE  AND  DECAY  OF  WOODS  273 

eventually  kills  the  tree.     Hardy  Catalpa,  White  Ash,  and  other 
trees  have  special  enemies.1 

"The  chestnut  blight  appears  to  confine  itself  to  attacks  upon  species 
of  the  genus  Castanea.  It  was  first  recognized  in  1905  in  trees  near 
New  York  City  but  has  now  spread  into  many  States  and  has  prac- 
tically killed  all  of  the  trees  that  have  been  attacked.  If  the  trunk  is 
the  part  affected,  the  tree  is  killed  perhaps  in  one  season,  but  if  the  small 
branches  are  attacked,  the  tree  may  survive  for  several  years.  The 
spores  produce  running  sores  and  the  trunks  or  branches  that  have  been 
girdled  by  these  sores  assume  a  characteristic  appearance.  One  of  the 
most  easily  detected  symptoms  is  the  growth  of  sprouts  or  " suckers" 
below  the  girdling  lesions  of  the  trunk  and  branches  as  well  as  at  the 
base  of  the  tree." 

Fungous  Diseases  of  Structural  Wood. — The  term  "structural 
woods"  here  includes  woods  that  are  ready  for  construction  and 
those  that  are  finally  in  place.  Life-processes  have  ceased  in  the 
woods  that  are  now  referred  to,  which  may  be  either  seasoned  or 
green.  The  fungous  enemies  of  such  material  are  very  numerous, 
and,  just  as  conditions  were  noted  under  which  all  fungi  thrive 
regardless  of  their  species,  so  here  it  is  more  practical  to  note  all 
of  the  ways  in  which  timbers  are  exposed  and  to  then  study  the 
influence  that  each  one  of  these  exposures  exerts  upon  the  life 
of  fungi. 

Structural  woods  may  be  exposed  in  four  ways.  They  are  as 
follows : 

First. — Woods  may  be  coated  by  paint,  metal,  plaster,  or  simi- 
lar materials. 

Second. — Woods  may  be  coated,  that  is  enclosed,  by  earth  or 
water. 

Third. — Woods  that  have  not  been  coated  may  be  exposed  to 
the  weather. 

Fourth. — Woods  that  have  not  been  coated  may  be  protected 
from  the  weather. 

The  "medium  conditions"  of  heat,  air,  and  moisture  mentioned 
as  necessary  for  the  development  of  fungi  are  secured  in  the  first 

^'Disease  of  Taxodium  known  as  Peckiness,"  von  Schrenk  (Contribu- 
tion 14,  Shaw  School  of  Botany);  "Two  Diseases  of  Red  Cedar,"  von  Schrenk 
(United  States  Division  Vegetable  Physiology  and  Pathology,  Bulletin  No. 
21);  "Diseases  of  Bull  Pine,"  von  Schrenk  (United  States  Bureau  of  Plant 
Industry,  Bulletin  No.  36);  "Diseases  of  the  Hardy  Catalpa"  (United  States 
Bureau  of  Forestry,  Bulletin  No.  37) ;"  Diseases  of  White  Ash,"  von  Schrenk 
(United  States  Bureau  of  Plant  Industry,  Bulletin  No.  32) ;  etc.,  etc. 


274  ORGANIC  STRUCTURAL  MATERIALS 

and  third  exposures.     Woods  are  comparatively  safe  when  in 
the  second  and  fourth  exposures. 

First  Exposure. — Paints  and  other  impervious  coatings  protect 
from  outside  conditions  but  are  detrimental  if  moisture  and  im- 
purities are  within  the  wood  when  it  is  coated.  Coatings  sea) 
up  the  moisture  and  impurities,  and  a  condition  known  as  "  dry- 
rot"  is  likely  to  occur.  It  should  be  noted  that  the  name  dry- 
rot  refers  to  the  results  of  the  disease.  The  wreckage  is  dry  and 
chalky  but  the  fungi  that  caused  this  wreckage  could  not  have 
lived  without  some  moisture. 

The  application  of  paint  to  an  organic  substance  such  as  wood  must 
be  distinguished  from  the  application  of  paint  to  an  inorganic  substance 
such  as  iron.  The  principles  that  here  apply  with  woods  resemble 
those  that  apply  when  fruits  or  meats  are  placed  in  cans.  Air-tight 
coatings  should  not  be  placed  around  any  of  these  organic  materials 
unless  they  have  first  been  sterilized,  cured,  or  otherwise  prepared. 

Second  Exposure. — This  exposure  is  distinct  from  the  one 
that  precedes  it  in  one  vitally  important  particular.  Paints 
and  metals  are  practically  inert,  while  mud  and  water  are  not. 
Mud  and  water  protect  from  outside  influences  but  at  the  same 
time  dilute  or  cleanse  away  such  impurities  as  have  remained 
within  the  wood.  Even  green  woods  are  safe  while  under  water, 
and  not  only  this,  but  changes  take  place  that  render  them  more 
durable  after  they  have  been  removed  from  the  water.1 

Woods  do  not  no  mally  decay  while  submerged  in  mud  or 
water.  Records  show  that  woodwork  has  lasted  in  this  manner 
for  over  a  thousand  years,  and  there  is  no  reason  why  it  should 
ever  decay  while  thus  protected.  The  softening  or  physical 
disintegration  that  takes  place  under  some  conditions  is  not 
decay. 

Third  Exposure. — The  third  exposure  is  associated  with  what 
is  commonly  known  as  " wet-rot."  The  fungi  that  act  when 
uncoated  woods  are  exposed  to  the  weather  seem  to  require  or 
to  tolerate  larger  quantities  of  moisture  than  those  accountable 
for  the  changes  known  as  dry-rot. 

The  medium  moisture  conditions  necessary  for  the  growth  of 
fungi  in  this  position  are  supplied  in  two  ways:  (1)  Excessive 
quantities  of  water  may  be  applied  intermittently  as  with 
marine  constructions  that  are  exposed  between  the  tides,  or  (2) 

1  See  index  for  "Water  Seasoning." 


PLATE  VI.  PORTION  OF  FLOOR  BEAM  AFTER  ATTACK  BY  DRY  ROT 

FUNGUS 


111 


i . 


Lifeless  Condition  of  Wood  is  Shown  by  Detached  Material  at  Bottom  of 

Picture. 

(Facing  page  274.) 


USE  AGE  AND  DECAY  OF  WOODS 


275 


smaller  quantities  of  water  may  be  present  constantly  as  when 
timbers  rest  upon  damp  soil,  and  when  they  are  exposed  to  the 
moist  atmosphere  of  mines. 

The  Influence  of  Top  Soil. — -This  is  so  great  that  the  expression, 
"  durable  in  contact  with  the  soil"  is  often  used  as  a  measure  of 
the  durability  of  wood.  Surface  soil  is  dangerous  for  several 
reasons.  It  is  damp,  and  comparatively  warm,  and  it  restricts 
the  air  but  does  not  cut  it  off  entirely.  Micro-organisms  are 
present  in  the  soil  near  the  surface. 

The  effect  of  contact  with  top-soil  is  shown  in  the  case  of  posts 
and  other  timbers  placed  upright  in  the  ground.  Decay  usually 
begins  in  the  parts  of  these  timbers  that  are  nearest  to  the  surface 
of  the  ground  and  later  extends  upward  and  downward  from  the 
surface  as  conditions  permit. 

The  tops  of  posts  and  similar  timbers  resist  because  they  are 
drained  and  well  ventilated,  and  the  bottoms  resist  if  they  are 
driven  down  deep  enough  to  escape  the  conditions  that  prevail 
at  the  surface.  A  beam  raised  a  short  distance  from  the  ground 
lasts  longer  than  one  lying  on  its  surface,  because,  although  the 
space  between  the  timber  and  the  soil  may  not  be  more  than  a 
few  inches,  it  is  enough  to  secure  some  drainage  and  ventilation. 

Some  woods  noted  for  extreme  durability,  average  durability, 
and  perishability  when  in  contact  with  the  soil,  are  noted  below. 
Weiss  estimates1  that  most  of  the  woods  in  the  first  column  will 


Very  durable  woods 


Durable  woods 


Perishable  woods 


Black  Locust 

Catalpa 

Cypress 

Greenheart 

Lignumvitse 

Mesquite 

Mulberry  Red 

Northern  White  Cedar 

Osage  Orange 

Redwood 

Western  Red  Cedar 


Chestnut 
Douglas  Fir 
Longleaf  Pine 
Southern  White  Cedar 
White  Oak 


Ash 

Balsam 

Basswood 

Beech 

Birch 

Cottonwood 

Hemlock 

Loblolly  Pine 

Lodgepole  Pine 

Red  Oak 

Sitka  Spruce 

Sycamore 

Tupelo 

Western  Yellow  Pine 

White  Spruce 


Preservation  of  Structural  Timber,"  Weiss  (p.  275). 


276  ORGANIC  STRUCTURAL  MATERIALS 

probably  last  more  than  twenty-five  years  when  in  contact  with 
the  soil;  that  most  of  those  in  the  second  column  will  last  between 
ten  and  twenty-five  years,  and  that  most  of  those  in  the  third 
column  will  fail  in  less  than  ten  years. 

Fourth  Exposure. — Uncoated  woods  do  not  normally  decay  as 
long  as  they  remain  protected  from  the  weather  in  dry,  venti- 
lated places.  On  the  contrary,  the  quality  of  wood  is  likely  to 
improve  under  such  conditions,  for  reasons  that  are  given  in  the 
section  devoted  to  "  Natural  Seasoning."  Many  of  the  timbers 
seen  in  the  covered  wooden  highway  bridges  that  were  erected 
in  this  country,  in  some  cases  more  than  one  hundred  years  ago, 
are  yet  sound.  Unpainted  wooden  roof-trusses  have  lasted  for 
many  centuries  in  European  churches. 


Evidence  of  Disease  in  Wood. — Disease  becomes  apparent  in 
many  ways.  Some  woods  discolor,  others  swell  and  soften,  while 
yet  others  become  dry  and  brittle.  Clots  of  hyphae  sometimes 
fill  cracks  or  appear  beneath  the  bark  of  logs.  Thick  masses  of 
orange,  pink,  or  gray  material  often  extend  like  giant  cobwebs 
between  rotting  timbers  in  mines.  Piles,  ties,  and  mudsills  may 
be  sound  without  but  soft  and  spongy  within.  Sometimes  this 
order  is  reversed. 

Methods  of  Treatment. — Preventative  methods  are  much  more 
valuable  than  curative  methods.  It  is  usually  impracticable  to 
attempt  to  control  disease  that  has  once  started.  It  is  said 
that  acid  solutions  will  counteract  some  kinds  of  fungi.  Disease 
caused  by  lack  of  ventilation  can  sometimes  be  prevented  from 
spreading  rapidly  by  providing  for  ventilation. 

Methods  of  Protection. — Fungous  diseases  are  contagious  and 
for  this  reason  diseased  woods  should  usually  be  destroyed.  The 
means  by  which  woodwork  may  be  more  or  less  successfully 
defended  against  fungus  diseases  are  as  follows:  (1)  Selection: 
Woods  that  have  the  fewest  fungus  enemies  should  be  selected. 

(2)  Seasoning:  Resistance   is   greatly  increased   by   seasoning. 

(3)  External  treatment:  Paints  and  other  coatings  may  be  used 
to  shut  out  the  micro-organisms  that  cause  disease.     (4)  Inter- 
nal treatment:  Woods  may  be  saturated  with  antiseptics.   These 
subjects  are  treated  elsewhere  under  appropriate  titles. 


CHAPTER  XI 

FAILURE  OF  WOOD  BECAUSE  OF  FIRE.     WOOD  AS  AN  AGENT  IN 
CONFLAGRATIONS.     FIRE  PROTECTION 

The  fact  that  wood  is  inflammable  is  of  far-reaching  impor- 
tance. The  direct  losses  caused  by  the  burning  of  finished  pro- 
ducts and  of  live  woods  in  the  forests,  and  the  indirect  losses 
caused  by  the  communication  of  fires  from  burning  wood  to  other 
property  cannot  be  estimated.  A  large  part  of  the  world's  incre- 
ment of  wealth  is  burned  up  every  year,  and  an  undue  proportion 
of  this  loss  occurs  in  the  United  States,  where  large  quantities 
of  wood  are  used  in  construction. 

Wood  is  a  principal  agent  in  conflagrations  for  the  reason  that 
it  is  the  only  one  of  the  primary  structural  materials  that  takes  fire 
at  ordinary  temperatures.  Stones  and  metals  may  fail  because 
of  fire,  but  they  do  not  contribute  directly  to  flames.  Many 
attempts  have  been  made  to  use  other  materials  in  place  of  wood 
in  naval  and  house  architecture  and  even  the  earliest  of  these 
attempts  were  due  to  the  fact  that  wood  will  burn. 

REFERENCES. — "Fire  Protection  of  Mills,  "  Woodbury  (John  Wiley  & 
Sons,  1895);  "Contributions  of  Chemistry  to  the  Methods  of  Preventing 
and  Extinguishing  Conflagrations,"  Norton  (Journal  of  American  Chemical 
Society,  Vol.  XVII,  1895) ;  Publications  of  National  Board  of  F\re  Under- 
writers; Publications  National  Fire  Protection  Association;  Files  of 
Insurance  Engineering;  "Process  of  Fireproofing  Wood  for  the  Wood- 
work of  Warships,"  Hexamer  (Engineering  News,  March  23,  1899);  "A 
New  Investigation  of  the  Fireproofing  of  Fabrics,"  Whipple  and  Fay  (Part 
of  "The  Safeguarding  of  Life  in  Theatres,"  Freeman,  Transactions  of  the 
American  Society  of  Mechanical  Engineers,  Vol.  27,  1906);  "Waste  of  Our 
National  Resources  by  Fire,"  Baker  (Proceedings  of  Meeting  called  jointly 
by  the  American  Society  of  Civil  Engineers,  the  American  Institute  of  Min- 
ing Engineers,  the  American  Society  of  Mechanical  Engineers,  and  the 
American  Institute  of  Electrical  Engineers,  published  in  pamphlet,  1909); 
"The  Enormous  Fire  Waste  of  the  United  States,"  Cochrane  (Scientific 
American,  June  15,  1912);  "Fire  Prevention  and  Fire  Protection,"  Freitag 
(John  Wiley  &  Sons,  1912);  "The  Modern  Factory,"  Price  (John  Wiley 
&  Sons,  1914);  "Tests  on  Inflammability  of  Untreated  Wood  and  of  Wood 
Treated  with  Fire-retarding  Compounds,"  Prince  (Report  on  Uses  of  Wood, 
National  Fire  Protection  Association,  1915). 

277 


278 


ORGANIC  STRUCTURAL  MATERIALS 


Fire  losses  are  greater  in  the  United  States  than  in  any  other 
country.  The  direct  losses  now  exceed  two  hundred  million 
dollars  every  year.  In  its  relation  to  the  building  operations  of 
the  country  this  is  equivalent  to  the  destruction  of  one  house  out 
of  about  every  four  built.1  This  loss,  which  is  about  equal  to  the 
total  value  of  all  gold,  silver,  copper,  and  petroleum  produced  in 
the  United  States  in  a  year,  and  which  is  many  times  greater 
than  the  interest  on  the  National  debt,  is  one  of  the  factors  in  the 
present  high  cost  of  living.  The  sum  mentioned  does  not  include 
indirect  losses,  or  losses  by  forest  fires. 

The  direct  fire  losses  in  the  United  States  for  thirty-six  years 
(1875-1910  inclusive),  as  estimated  by  the  National  Board  of 
Fire  Underwriters,  were  as  follows : 


1875  
1876  
1877  
1878 

.  ..  $78,102,285 
.  .  .  64,630,600 
.  .  .  68,265,800 
64  315  900 

1889.  . 
1890.  . 
1891.. 
1892 

.  $123,046,833 
.  108,993,792 
.  143,764,967 
151  516  098 

1903.  .  .  . 
1904.  .  .  . 
1905.... 
1906 

$145,302,155 
229,198,050 
165,221,650 
518  611  800 

1879  
1880  
1881  
1882  
1883 

...  77,703,700 
...  74,643,400 
.  .  .  81,280,900 
.  .  .  84,505,024 
100  149  228 

1893.. 
1894.. 
1895.. 
1896.. 
1897 

.  167,544,370 
.  140,006,484 
.  142,110,233 
.  118,737,420 
116  354  575 

1907.... 
1908.... 
1909.... 
1910.... 

215,084,709 
217,885,850 
188,705,150 
214,003,300 

1884 

110  008  611 

1898 

130  593  905 

1885  
1886  
1887 

.  .  .  102,818,796 
.  .  .  104,924,750 
120  283  055 

1899.. 
1900.  . 
1901 

.  153,597,830 
.  160,929,805 
165  817  810 

Over  five 
direct  lo 
six  year 

billion  dollars 
sses  in  thirty- 

5 

1888  

.  .  .  110,885,665 

1902 

161  078  040 

Fire  losses  are  increasing  faster  than  the  population  of  the 
country  is  increasing,  that  is,  the  number  of  fires  per  capita  is 
increasing. 

The  indirect  losses  that  take  place  as  a  result  of  fire  must  be 
considered  also.  Such  losses  include  the  costs  of  maintaining 
fire  departments  and  water  supplies  for  purposes  of  fire  fighting, 
excessive  insurance  and  losses  in  rents  and  business.  It  is 
estimated  that  in  1907  the  total  direct  and  indirect  losses  from 
fire  amounted  to  $456,485,900,  a  sum  almost  half  as  great  as  the 
value  of  the  new  building  constructions  for  that  year.  That  is  to 

1  "Proceedings  of  the  Forty-ninth  Annual  Meeting  of  the  National  Board 
of  Fire  Underwriters,"  p.  19.  Report  "National  Conservation  Commission, 
Section  of  Minerals,"  Washington,  December,  1908. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS       279 

say,  during  that  year  about  one  billion  dollars  was  expended 
upon  new  buildings  and  construction  work,  and  approximately 
half  of  this  increment  was  destroyed  by  fire.  Such  a  sum  is 
greater  than  the  true  value  of  the  real  property  and  improvements 
in  any  one  of  the  States  of  Maine,  West  Virginia,  North  Carolina, 
North  Dakota,  Alabama,  Louisiana,  and  Montana.1 

There  is  also  the  loss  of  human  life.  According  toft-he 
United  States  Census,  6,000  persons  died  of  burns  and  10,000 
persons  were  badly  injured  by  the  same  cause  during  1906. 

All  comparisons  in  connection  with  this  subject  are  startling, 
yet  all  of  them  are  conservative.  Baker  estimates  that  the 
buildings  destroyed  every  year  in  the  United  States  if  placed 
upon  lots  with  an  average  frontage  of  65  feet,  would  line  both 
sides  of  a  street  long  enough  to  extend  from  New  York  to  Chicago.2 

"Picture  yourself  driving  along  this  terribly  desolated  street.  At 
every  thousand  feet  you  pass  the  ruins  of  a  building  from  which  an 
injured  person  was  rescued.  Every  three-quarters  of  a  mile  there  is 
the  blackened  wreck  of  a  house  in  which  some  one  was  burned  to  death." 

' 'Imagine  this  street  before  the  fire  touched  it,  lined  with  houses, 
stores,  factories,  barns,  schools,  churches.  Suppose  the  fire  starts  at  one 
end  of  the  street  on  the  first  day  of  January  and  is  steadily  driven  forward 
by  a  high  wind,  just  as  actually  happens  in  a  conflagration.  Building 
after  building  takes  fire;  and  while  the  fire  fighters  save  some  in  a  more 
or  less  injured  condition,  the  fire  steadily  eats  its  way  forward  at  the  rate 
of  nearly  three  miles  a  day,  for  a  whole  week,  for  a  whole  month,  for  all 
twelve  months  of  the  year.  And  at  the  end  of  1907  did  the  conflagra- 
tion end?  No;  it  began  on  a  new  street,  a  thousand  miles  long,  which 
was  likewise  destroyed  when  1908  was  ended.  And  this  same  destruc- 
tion is  going  on  today." 

The  gravity  of  the  situation  is  also  expressed  by  Merrill  as 
follows : 

"Fifteen  years  is  a  brief  space  of  time  in  the  history  of  an  organiza- 
tion; it  is  briefer  in  the  history  of  a  nation.  Yet  for  our  country,  this 
period  includes  the  San  Francisco,  Baltimore,  Chelsea  and  Bangor  con- 
flagrations, the  Windsor,  Iroquois,  Collingswood,  Boyertown,  Slocum, 

1  "The  Enormous  Fire  Waste  of  the  United  States,"  Cochrane  (Scientific 
American,  June  15,  1912). 

2  Proceedings  of  meeting  called  jointly  by  The  American  Society  of  Civil 
Engineers,  The  American  Institute  of  Mining  Engineers,  The  American 
Society  of  Mechanical  Engineers,  and  The  American  Institute  of  Electrical 
Engineers,  March  24,  1909. 


280  ORGANIC  STRUCTURAL  MATERIALS 

Lenox,  Cherry,  Newark,  Chicago.  Stock  Yards  and  Asch  disasters;  not 
a  day  without  its  long  list  of  properties  destroyed  and  not  a  month 
without  record  of  the  sacrifice  of  human  life.  It  marks  a  burnt  offering 
of  more  than  two  thousand  million  dollars  worth  of  our  created  sources, 
and  the  lives  of  more  than  twenty  thousand  of  our  people."1 

A  comparison  between  per  capita  losses  in  some  European 
countries  and  those  in  the  United  States  is  as  follows  (National 
Board  of  Fire  Underwriters) : 

Austria  (1898-1902)  $0.29         Italy  (1901-1904) $0.12 

Denmark  (1901) 0.26  Switzerland  (1901-1903)  .  .  .     0.30 

France   (1900-1904) 0.30        United  States 2.50 

Germany  (1902) 0.49 

In  other  words,  the  average  per  capita  loss  in  six  leading  Euro- 
pean countries  is  thirty  cents,  while  the  average  per  capita  loss  in 
the  United  States  is  two  dollars  and  fifty  cents. 

No  country,  however  rich,  can  afford  to  suffer  such  losses 
indefinitely;  yet  no  great  decrease  can  be  expected  until  the 
average  building  in  the  United  States  is  as  good,  from  the  fire- 
resisting  viewpoint,  as  the  average  building  in  European  coun- 
tries. Most  of  the  structures  erected  to  meet  first  needs  in  the 
United  States  were  built  of  wood;  and  this,  with  the  indiscrimi- 
nate use  of  wood  in  construction  at  the  present  time,  is  the  prin- 
cipal explanation  of  why  losses  in  this  country  have  been  and  are 
so  heavy.  The  policy  in  Europe  is  to  prevent  fires;  but  in  this 
country,  until  recently,  chief  attention  was  given  to  perfecting 
apparatus  and  organizations  by  which  fires  might  be  extinguished. 

The  present  subject  is  part  of  the  general  field  of  Fire  Protec- 
tion. The  behavior  of  wood  while  burning  and  its  influence  upon 
the  situation  as  a  whole  must  be  comprehended,  but  some  knowl- 
edge of  the  wider  field  of  which  the  present  subject  forms  a  part 
will  also  be  of  service.  The  notes  that  follow  will  relate  to  (1) 
Wood  as  an  Agent  in  Conflagrations  and  (2)  Some  Principles  of 
Fire  Protection. 

WOOD  AS  AN  AGENT  IN  CONFLAGRATIONS 

This  part  of  the  subject  divides  itself  as  it  relates  to  the  burning 
of  wood,  the  attempts  to  prevent  wood  from  burning,  and  the  methods 
used  to  extinguish  burning  wood. 

1  The  great  conflagrations  that  have  taken  place  in  the  last  and  present 
centuries  are  listed  on  p.  272  of  World's  Almanac,  1911. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  281 

THE  BURNING  OF  WOOD.— Wood  consists  of  a  definite 
chemical  compound  known  as  cellulose,  permeated  by  materials 
collectively  known  as  lignin,  and  secretions  such  as  resins,  color- 
ing matter,  and  water.  Or,  in  terms  of  inorganic  chemistry,  it 
consists  of  carbon,  oxygen,  hydrogen,  nitrogen,  and  small 
amounts  of  mineral  salts  that  exist  in  the  ash. 

Upon  burning,  wood  first  gives  off  some  water,  after  which 
inflammable  gases  separate  from  a  solid  base  of  carbon;  the  carbon 
is  next  largely  consumed  and  leaves  a  residue  of  ash,  which  is 
composed  of  metallic  salts  that  were  originally  present,  together 
with  carbonates  formed  during  the  burning.  Wood  deteriorates 
and  may  then  take  fire  spontaneously1  when  subjected  to  com- 
paratively slight  elevations  of  temperature  for  long  periods.  In 
most  cases,  however,  wood  takes  fire  from  flame  communicated 
directly.  Complex  changes  take  place  in  wood  as  the  result  of 
heating  without  access  of  air.  They  are  described  as  follows:2 

"When  wood  is  heated  in  retorts,  the  moisture  is  driven  out,  but  no 
decomposition  occurs  until  the  temperature  approaches  160  degrees  C. 
Between  160  degrees  and  275  degrees  C.  a  thin  watery  distillate  is 
chiefly  formed;  above  275  degrees  the  yield  of  gaseous  products  becomes 
marked,  and  between  350  degrees  and  450  degrees  liquid  and  solid  hydro- 
carbons are  extensively  formed.  Above  this  last  temperature  little 
change  occurs,  and  charcoal,  containing  the  mineral  ash,  remains  in  the 
retort. 

"The  fraction  between  160  degrees  and  275  degrees  is  called  pyrolig- 
neous  acid,  and  contains  the  important  liquid  distillates,  methyl  (wood 
alcohol),  acetic  acid,  together  with  acetone,  methyl  acetate,  allyl  alcohol, 
phenols,  and  a  great  many  other  substances. 

"The  fraction  between  275  degrees  and  450  degrees  contains  both 
aromatics  (i.e.,  benzene  derivatives)  and  parafnne  hydrocarbons.  Its 
most  important  constituent,  from  a  commercial  point  of  view,  is  the 
creosote  oil,  containing  guaiacol,  creosol,  and  other  phenols  of  high 
molecular  weight. 

"The  variety  of  wood  used  affects  the  amount  of  distillate.  Decidu- 
ous trees,  especially  birch,  oak,  and  beech,  are  preferred.  Coniferous 
woods  afford  less  acid  (watery)  distillate,  but  more  of  the  higher  frac- 
tions containing  turpentine  and  resin." 

1  Wood  should  not  come  into  contact  with  steam  or  hot  water  pipes  and 
should  not  be  placed  too  near  registers;  otherwise  deterioration  and  spon- 
taneous combustion  may  result.     See  also  "Spontaneous  Ignition  of  Wood," 
Fairweather  (Insurance  Engineering,  September,  1908.) 

2  Quotation  from  Thorp's  "Outlines  of  Industrial  Chemistry." 


282  ORGANIC  STRUCTURAL  MATERIALS 

ATTEMPTS  TO  PREVENT  WOODS  FROM  BURNING 

Many  attempts  have  been  made  to  prevent  woods  from  burning. 
The  ancient  Greeks  used  alum  for  this  purpose;  and  later  at- 
tempts were  associated  with  methods  designed  to  protect  woods 
from  decay.  At  the  present  time  the  most  intelligent  efforts  are 
those  that  have  followed  great  theater  fires,  and  much  of  the 
literature  upon  this  subject  relates  to  efforts  that  have  been  made 
to  protect  the  woods  and  fabrics  used  in  theaters.  The  tendency 
now  is  to  eliminate  woods  and  other  combustible  materials  for 
theater  buildings. 

Woods  treated  with  certain  chemicals  are  referred  to  as  "fire- 
proofed  woods,"  but  this  is  inaccurate.  All  woods  burn  under 
the  right  conditions,  and,  at  best,  it  is  possible  only  to  retard 
oxidation,  and  to  obstruct  for  a  little  the  escape  of  volatile  gases 
that  are  active  agents  in  spreading  fires.  Correctly  speaking 
fireproof ed  woods  do  not  exist;  it  is,  however,  correct  to  speak 
of  methods  that  retard  burning.  Protective  methods  are  of  two 
kinds:  fire-retarding  chemicals  are  applied  internally  and 
externally. 

INTERNAL  PROTECTION.— The  attempts  made  to  protect 
woods  from  fire  by  injecting  fire-retarding  chemicals  into  them  have 
not  yielded  satisfactory  results;  yet  the  fact  exists  that  such  at- 
tempts have  been  made  and  a  statement  with  regard  to  this  form  of 
protection  is,  therefore,  necessary.1  The  subject  will  be  divided 
as  follows:  the  materials  known  as  fire  retardants,  the  processes 
used  to  introduce  these  materials  within  the  woods,  and  the 
selection  and  preparation  of  woods  that  are  to  receive  the  fire- 
retardant  chemicals. 

Fire  Retarding  Materials. — Alum^  boric  acid,  borax,  sodium 
tungstate,  water  glass,  magnesium  phosphate,  aluminum  sulphate, 
ammonium  chloride,  ammonium  sulphate,  ammonium  phosphate, 
"  Paris  theatre  solution,"  "  Chicago  solution,"  and  many  other 
mixtures  and  compounds  have  been  considered  or  used  to  retard 
the  burning  of  fabrics  and  the  burning  of  woods.  Some  of  these 
substances  serve  because  they  decompose  and  liberate  gases  that 
smother  flame.  Borax  owes  its  efficiency  to  other  properties; 
it  melts  easily  and  then  flows  in  thin  films  that  cut  off  the  supply 
of  oxygen  from  burning  wood. 

1  Fireproof  ed  woods  were  used  in  ships,  notably  after  the  war  with  Spain. 
A  small  quantity  of  fireproofed  wood  has  been  used  in  the  finish  of  special 
buildings.  At  the  present  time  the  demand  for  such  material  is  limited. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  283 

The  value  of  ammonium  phosphate  as  a  fire  retardant  has  been 
recognized  for  many  years.  In  his  report  upon  the  burning  of 
the  Iroquois  Theatre,  Freeman  states  that  no  one  of  the  many 
salts  or  mixtures  tested  was  found  to  be  so  good.  The  properties 
and  behavior  of  this  salt  are  described  in  the  following  quotation. 

"  First,  it  has  a  little  tendency  to  gather  dampness,  and  to  dry  this 
out  absorbs  a  little  heat.  Next,  as  the  heat  rises,  ammonia  is  given  off, 
and  the  thin  film  of  this  repels  the  oxygen  of  the  air.  When  the  am- 
monia is  gone  we  have  left  the  ortho-phosphoric  acid,  which  in  liquid 
form  covers  the  surface  and  preserves  it  from  oxidation  under  increasing 
heat.  At  300  to  400  degrees  Fahrenheit  this  decomposes,  giving  off 
water;  at  higher  temperatures  it  gives  off  its  remaining  water.  In  all 
of  this  disassociation  it  absorbs  some  heat  until  we  have  left,  at  full  red 
heat,  fused  metaphosphoric  acid  as  a  liquid  film  surrounding  the  fixed 
carbon  remaining  from  the  destructive  distillation. 

"On  the  other  hand,  the  phosphate  of  ammonia  has  its  disadvantages. 
A  manufacturing  chemist,  perhaps  of  the  widest  experience  of  any  in 
this  country  in  the  practical  chemistry  of  the  phosphates,  warns  me 
that  for  its  best  efficiency  it  must  be  applied  in  a  strong  or  saturated 
solution,  but,  if  very  strong,  it  may  in  time  disastrously  affect  the 
strength  of  the  fiber,  that  it  is  somewhat  deliquescent,  has  a  tendency 
to  develop  fungous  growth,  that  in  time  it  may  part  with  a  portion  of 
its  ammonia,  becoming  the  acid  ammonium-phosphate  which  has  a 
tendency  in  presence  of  moisture  to  attack  metals,  while  in  a  warm 
atmosphere  the  free  phosphoric  acid  attacks  some  colors." 

The  result  of  a  series  of  experiments  upon  the  comparative 
worth  of  the  several  chemical  substances  and  mixtures  used  as 
fire  retardants,  conducted  by  Whipple  and  Fay,  is  summarized 
as  follows:1 

(a)  That  inert  chemical  substances  can  exert  but  very  slight  fire- 
retarding  action. 

(6)  The  fire-retarding  action  of  salts  which  depend  for  fire-retardant 
quality  only  upon  their  water  of  crystallization,  like  potash,  alum, 
sodium  phosphate  and  borax,  is  slight  and  unimportant,  although  some- 
what superior  to  that  of  inert  substances. 

(c)  Fire  retardants  of  the  class  which  suffer  chemical  decomposition 
under  heating  are  decidedly  more  efficient  than  those  which  depend  on 
the  driving  off  of  water  of  crystallization,  but  still  far  less  efficient  than 
the  class  that  follows. 

(d)  The  most  efficient  salts  are  those  which  on  decomposing  leave 

iaA  New  Investigation  of  the  Fireproofing  of  Fabrics"  contained  in 
"The  Safeguarding  of  Life  in  Theatres,"  Freeman  (pp.  57-65). 


284  ORGANIC  STRUCTURAL  MATERIALS 

behind  a  non-volatile  residue  which  is  fluid  at  the  temperature  of  the 
burning  canvas,  and  covers  the  charring  fabric  with  a  thin  glaze  which 
prevents  further  access  of  air;  and,  of  this  type,  phosphate  of  ammonium 
was  found  to  be  the  best. 

It  is  necessary  to  distinguish  between  chemicals  injected  into 
woods  as  fire  retardants  and  those  that  are  applied  within  woods 
for  other  purposes.  The  latter  are  antiseptics,  and  woods  are 
the  better  for  their  presence;  but  as  distinct  from  these  the  salts 
which  are  applied  as  fire  retardants  attract  water  and  in  this  way 
injure  woods. 

Processes  Used  to  Apply  Fire  Retardants  Within  Woods. — The 
methods  used  to  introduce  fire  retardants  within  woods  are  the 
same  as  those  employed  to  introduce  antiseptics  within  woods. 
There  should  be  deep  impregnation  and  the  wood  must  not  be 
injured.  Processes  are  of  two  kinds:  there  are  some  that  do  not 
include  pressure,  and  others  that  do  include  pressure.  Solu- 
tions may  be  applied  by  dipping,  brush-applications,  and  the 
open  tank  process;  or  they  may  be  forced  in  by  pressure  applied 
within  cylinders. 

Preparation  of  Woods  to  Receive  Fire  Retardants. — Woods 
should  be  dry  and  receptive  if  fire  retardants,  or  any  other  chemical 
substances,  are  to  be  introduced  within  them.  Some  attention 
should  be  paid  to  selection;  it  should  be  remembered  that  woods 
differ  in  receptivity  and  that  some  woods,  such  as  California 
redwood,  take  fire  less  easily  than  others. 

EXTERNAL  PROTECTION. — Many  attempts  have  been  made 
to  prevent  or  retard  the  burning  of  wood  by  means  of  coatings,  and 
at  least  one  of  these  attempts  has  succeeded  sufficiently  to  serve 
practically  in  construction.1  The  properties  of  the  materials 
employed,  the  methods  by  which  they  are  applied,  and  the  prepa- 
ration of  woods  to  receive  them,  must  be  considered. 

Materials. — Fire-retardant  coatings  are  of  many  kinds.  An 
ideal  fire-coating  is  one  that  resists  the  disintegration  and  dis- 
tortion due  to  high  heat  and  sudden  cooling,  and  one  that  will 
not  conduct  heat.  The  materials  available  for  this  purpose  do 
not  meet  these  requirements  satisfactorily,  but  they  do  resist  the 
action  of  fire  longer  than  other  materials.  Asbestos,  the  so-called 
fireproof  paints,  and  certain  metals,  are  used  in  fire-coatings. 

Asbestos. — The  name  asbestos  is  applied  to  several  products, 
as  Canadian  asbestos  or  chrysotile,  which  contains  about  fifteen 

1  See  description  of  fire  doors  and  fire  shutters. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS 


285 


per  cent,  of  water,  and  tremolite,  a  fibrous  calcium  silicate,  which 
contains  no  water.  Canadian  asbestos,  so  largely  used  in  the 
United  States,  loses  strength  and  is  otherwise  altered  by  tem- 
peratures, just  below  red  heat,  that  are  sufficient  to  expel  the  water 
of  crystallization.1 

The  fact  that  common  asbestos  becomes  brittle  and  loses 
strength  when  subjected  to  comparatively  low  temperatures  has 
discouraged  its  use  in  making  curtains  to  isolate  the  woodwork 
and  other  inflammable  materials  used  in  theaters,  and  such  cur- 
tains although  still  used,  are  no 
longer  regarded  as  the  best  form 
of  protection.2  Tenacity  is  less 
important  if  asbestos  is  to  be 
used  as  a  pigment  in  paint. 

Fireproof  Paints. — Fireproof 
paints  differ  from  ordinary 
paints  chiefly  in  that  they  are 
not  themselves  inflammable. 
These  paints  offer  momentary 
but  sometimes  sufficient  resist- 
ance to  very  small  fires,  such 
as  flames  from  burning  matches. 
But  they  do  not  resist  fires 
that  have  gained  headway  or 
created  appreciable  draughts. 
It  is  obvious  that  crusts  less 
than  one  one-hundredth  of  an 
inch  in  thickness  cannot  aid  effectively  any  attempts  to 
prevent  conflagrations. 

Lime  and  asbestos  are  common  pigments,  while  glue  and  water- 
glass  are  common  vehicles.  Oil  should  not  be  used.  A  number 
of  mixtures  purchased  in  open  market  were  found  upon  analysis3 
to  consist  chiefly  of  slaked  lime,  powdered  asbestos,  alum,  gyp- 
sum, and  glue.  A  cold  water  paint  containing  a  lime,  asbestos, 
or  magnesium  base,  and  casein  or  glue  as  a  binder,  is  doubtless 
as  good  as  any.  Although  the  National  Fire  Protection  Asso- 
ciation considers  well-made  whitewash  a  good  fireproof  coating, 

1  About  600  degrees  C. 

2  Steel  now  enters  into  the  construction  of  the  best  curtains  for  proscenium 
openings. 

3  Whipple  and  Fay  Report. 


FIG.  45. — Corner  of  tin-clad 
door. 


286  ORGANIC  STRUCTURAL  MATERIALS 

the  use  of  whitewash  for  this  purpose  is  not  general.  Some 
fire-retardant  paints  are  said  to  be  composed  of  easily  fusible 
glass  mixed  with  ordinary  paint. 

Metals. — Wood  is  sometimes  enclosed  by  metal.  Combina- 
tions of  wood  and  tin,  such  as  are  used  for  fire  doors  and  fire 
shutters,  have  resisted  where  solid  metal  has  buckled  and  failed.1 
Tin  is  superior  to  paint  in  that  it  resists  for  some  time  even  when 
exposed  to  severe  heat,  whereas  paints  offer  but  momentary 
resistance  even  to  very  small  fires.  Paints  soon  blister  and  chalk 
under  the  influence  of  heat. 

Methods  Used  to  Apply  Fire  Coatings. — Fire-retardant  paints 
are  applied  to  surfaces  of  wood  in  the  same  way  as  other  paints. 
That  is,  it  is  important  that  the  wood  should  be  clean,  dry,  and 
receptive;  that  the  brush  should  be  held  at  right  angles  to  the 
surface.,  and  that  the  paint  should  be  laid  on  with  strokes 
parallel  to  the  grain  of  the  wood.2 

Tin  can  be  applied  to  wood  in  such  a  way  that  the  two  together 
offer  a  very  real  resistance  to  fire.  Tin  will  warp,  and  wood  will 
burn,  but  the  two,  when  used  together  in  standard  fire  doors,  have 
lasted  long  enough  to  save  buildings.  They  have  retained  the 
shapes  of  the  openings,  even  after  the  wood  within  has  charred 
and  failed.  Standard  fire  doors  are  made  of  not  less  than  three 
layers  of  seven-eighths-inch  wood.  The  tin  covers  overlap  at 
all  points  so  as  to  protect  fastenings  and  resist  strains.3 

The  principles  that  apply  when  woods  are  to  be  coated  with 
ordinary  paints  and  varnishes  apply  equally  when  they  are  to 
receive  fire  coatings.  All  woods  should  be  well  seasoned,  dry, 
and  clean,  if  they  are  to  receive  coatings  of  any  kind,  and  no  wood 
that  is  moist,  knotty,  or  resinous  should  ever  be  used  in  any 
fire  door  or  fire  shutter.  Moisture  if  present  would  cause  decay, 
while,  if  a  fire  should  take  place,  moisture  and  resins  would  form 
hot  gases  that  would  burst  through  the  tin.  Clean,  dry,  white 
pine  is  used  in  the  best  fire  doors. 

Methods  of  Testing  "  Fireproof ed"  Woods. — Small  specimens 
are  usually  burned  in  laboratories4  and  the  intervals  that  elapse 
before  they  are  charred  or  consumed  are  taken  as  measures  of 
their  resistance.  Although  encouraging  results  are  obtained  in 

1  See  descriptions  of  fire  doors. 

2  See  "Paints  and  Varnishes  Applied  to  Surfaces  of  Woods." 

3  See  Rules  and  Requirements  National  Board  of  Fire  Underwriters. 

4  Bunsen  burners  are  commonly  employed. 


PLATE  VII.  APPEARANCE  OF  FIRE  DOORS  AFTER  FIRE 


(Facing  page  286.) 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  287 

this  way,  such  tests  have  very  little  practical  value  save  as  they 
enable  comparisons,  because  all  wood  whether  protected  or  not 
will  burn  if  the  draught  is  sufficient. 

The  way  in  which  results  are  influenced  by  methods  is  shown 
in  the  case  of  some  experiments  upon  so-called  fireproofed  canvas 
prepared  for  use  in  the  scenery  of  theatres.  These  experiments 
are  described  as  follows:1 

"In  the  effort  to  more  nearly  follow  practical  conditions,  one  set  of 
tests  was  developed  on  the  line  of  my  earlier  stovepipe  experiment  by 
burning  fireproofed  canvas  within  a  piece  of  five-inch  stovepipe  two  feet 
long  lined  with  asbestos."  "Six  strips  of  the  canvas,  thoroughly  treated 
with  the  different  solutions,  were  placed  three-fourths  of  an  inch  apart 
and  ignited  by  burning  one  ounce  of  excelsior.  In  every  case  the  canvas 
burned  completely  to  ash  in  from  three-fourths  of  a  minute  to  one  and  one- 
half  minutes,  with  flames  which  often  extended  two  feet  above  the  top  of  the 
stovepipe.  Tests  in  the  stovepipe  apparatus  on  the  efficiency  of  different 
flameproofing  chemicals  were  made  comparable  by  taking  the  same 
quantity  of  canvas  in  each  and  by  lighting  the  fire  with  the  same  quan- 
tity of  combustible." 

METHODS  USED  TO  EXTINGUISH  BURNING  WOODS.— 

Although  the  methods  used  to  extinguish  all  fires  are  the  same, 
yet  there  is  good  reason  for  associating  such  methods  with  the 
burning  of  wood. 

As  already  stated,  in  Europe  the  policy  with  regard  to  fires 
is  to  endeavor  to  prevent  them.  Less  wood  is  used  in  Europe 
and  the  losses  there  are  smaller  than  in  the  United  States,  where 
larger  quantities  of  wood  are  used  and  the  losses  that  take  place 
by  fire  are  larger.  In  the  United  States,  until  recently,  more 
attention  has  been  given  to  perfecting  apparatus  and  organiza- 
tions designed  to  extinguish  fires,  than  to  means  by  which  the 
fires  might  be  prevented. 

Fire  departments  in  Europe  are  inferior  to  those  in  the  United 
States,  because  less  need  exists  for  fire  departments  in  Europe. 
Those  who  visit  European  cities  for  any  length  of  time  are 
impressed  by  the  fact  that  fire  engines  are  so  seldom  seen.  Dur- 
ing ten  years  passed  in  French  and  German  cities  Norton  saw 
fire  engines  called  out  five  times.2  American  efficiency  in  the 

1  "A  New  Investigation  of  the  Pireproofmg  of  Fabrics"  contained  in  "The 
Safeguarding  of  Life  in  Theaters,"  Freeman  (pp.  57-65). 

2  Journal  of  the  American  Chemistry  Society  (Vol.  XVII,  No.  2). 


288  ORGANIC  STRUCTURAL  MATERIALS 

field  of  extinguishing  fires  is  unquestioned;  but  this  is  because  the 
demands  upon  firemen  are  so  great  in  the  United  States. 

Materials. — The  materials  used  to  extinguish  fires  act  by 
excluding  air  from  the  substances  that  are  burning.  It  is  need- 
less to  say  that  water  is  the  cheapest,  most  effective,  and  most 
widely  available  material  for  this  purpose;  it  should  not  be  for- 
gotten, however,  that  other  materials  are  sometimes  used.  Some 
of  these  are  as  follows: 

Carbon  Dioxide. — It  is  generally  conceded  that  much  of  the  value 
of  this  gas,  when  mixed  with  water  as  in  the  discharge  from  chemical 
extinguishers,  is  due  to  the  power  generated,  which  propels  the  stream. 
Carbon  dioxide  is  usually  used  mixed  with  water.  It  is  very  rarely  used 
by  itself. 

Sulphur  Dioxide  and  Ammonia. — These  gases  extinguish  fires  but  are 
seldom  used  because  it  is  often  inconvenient  to  obtain  and  apply  them 
and  because  they  endanger  life.  They  serve  because  they  displace  oxy- 
gen but  they  cannot  be  used  easily  save  in  enclosed  spaces  of  limited 
extent. 

Carbon  Tetrachloride. — The  properties  of  this  compound  were  known 
in  the  past  but  until  recently  its  usefulness  has  been  limited  by  its  high 
cost.  The  development  of  electrolytic  cells  for  the  production  of  chlo- 
rine and  caustic  soda,  with  the  consequent  cheapening  of  chlorine  gas, 
has  recently  opened  the  way  for  the  cheaper  manufacture  of  carbon 
tetrachloride.1  Carbon  tetrachloride  is  a  clear,  colorless,  volatile  liquid, 
having  a  specific  gravity  of  1.604  and  a  boiling  point  of  78  degrees  C: 
It  is  non-inflammable,  non-explosive,  non-corrosive,  and  its  vapors 
smother  flame.  It  is  a  non-conductor  and  is  particularly  useful  in  the 
case  of  electrical  fires,  where  water  cannot  be  employed  and  where  dry 
powders,  such  as  sand,  have  previously  been  used.  It  is  also  serviceable 
in  library  fires,  because  it  will  extinguish  flames  produced  by  burning 
papers  without  injuring  the  papers  as  water  would  injure  them. 

Solids. — Flour,  sand,  and  other  solids  are  sometimes  used  in  emergen- 
cies. Such  materials  are  stored  in  cylinders  and  these  "dry  powder 
cylinders"  are  convenient  and  easily  found  receptacles  for  small  quan- 
tities ofthe  powders  used.  These  cylinders  are  useful  as  far  as  they  go 
but  the  y  may  do  harm  by  causing  a  sense  of  security  not  warranted  by 
the  results  obtained.  The  National  Fire  Protection  Association  reports 
as  follows: 

"In  view  of  the  fatct  that  several  so-called  fire  extinguishers,  consist- 
ing generally  of  sheet-metal  tubes  filled  with  mixtures  of  bicarbonate  of 

1  Journal  Industrial  and  Engineering  Chemistry  (January,  1910) ;  Engineer- 
ing News  (March  16,  1911);  Quarterly  National  Fire  Protection  Association 
(January,  1911);  Catalogues  Pyrene  Manufacturing  Company;  etc. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  289 

soda  and  other  materials  in  powdered  form,  have  been  widely  advertised 
as  suitable  for  use  for  fire-extinguishing  purposes,  we  have  to  report 
that  in  our  opinion  all  forms  of  dry-powder  fire  extinguishers  are  inferior 
for  general  use,  that  attempts  to  extinguish  fires  with  them  may  cause 
delay  in  the  use  of  water  and  other  approved  extinguishing  agents,  and 
therefore  their  introduction  should  not  be  encouraged." 

Methods  or  Devices  for  Applying  Materials. — Water  is  applied 
by  steam  fire  engines  and  other  devices  commonly  associated 
with  the  elaborate  fire  departments  of  cities.  Tanks  placed 
at  high  elevations  are  often  useful  where  natural  head  is  not 
available.  Chemical  engines,  sprinklers,  and  fire  pails  are  also 
employed. 

Chemical  engines  are  tanks  containing  bicarbonate  of  soda 
dissolved  in  water,  and  commercial  sulphuric  acid  (oil  of  vitriol) 
stored  separately  but  also  within  the  tank.  The  carbon  dioxide 
which  results  when  these  compounds  come  together  creates  the 
force  by  which  the  contents  of  the  extinguisher  is  discharged.1 

Automatic  sprinkler  systems  consist  of  pipes  arranged  on  the 
ceilings  of  rooms  within  the  structures  to  be  protected.  Water- 
ways in  these  pipes  are  closed  by  small  discs  which  are  held  in 
place  by  easily  fusible  solder.  In  case  of  fire  the  solder  melts, 
water  flows  upon  the  fire,  and  an  alarm  is  rung.  There  are  many 
other  important  details,2  some  of  which  are  noted  later  in  the 
present  chapter. 

Portable  chemical  fire  extinguishers  differ  from  the  larger 
chemical  engines  that  have  been  described  in  that  they  are  easily 
carried  from  place  to  place,  and  very  easily  manipulated.  The 
copper  receptacle,  coated  with  tin,  is  designed  to  hold  about  three 
gallons  of  water,  and  to  resist  a  pressure  of  about  four  hundred 
pounds,  although  the  pressure  seldom  exceeds  eighty  pounds. 
The  quantities  of  acid  and  soda  are  adjusted  so  that  the  pressure, 
when  they  come  together,  is  not  greater  than  the  cylinders  can 
bear.  The  solution  that  leaves  the  extinguisher  should  be  alka- 
line rather  than  acid,  since  acid  solutions  are  more  liable  to 
damage  the  materials  upon  which  they  are  thrown.  Extin- 

1  Requirements  for  Proper  Installation  of  Chemical  Fire  Extinguishers 
(Published  by  The  New  York  Fire  Insurance  Exchange,  19 13). 

2  Rules  and  Requirements  of  the  National  Board  of  Fire  Underwriters 
for  Sprinkler  Equipment,  1913. 


290  ORGANIC  STRUCTURAL  MATERIALS 

guishers  should  be  recharged  at  stated  intervals;  their  contents 
should  always  be  fresh  and  active.1 

The  extinguishers  become  active  when  they  are  inverted. 
The  stopper  then  drops  away  from  the  mouth  of  the  acid  flask. 
The  acid  mixes  with  the  soda  solution,  and  the  conditions  neces- 
sary for  operation  are  obtained.  Extinguishers  should  not  be 
inverted  until  operators  are  in  the  presence  of  the  fires,  since  the 
streams  last  only  about  eighty  seconds.  They  should  be  stored 
in  conspicuous  places,  where  those  who  are  to  use  them  can  find 
them  easily.  Care  should  be  taken  so  their 
contents  will  not  freeze. 

Fire  pails  are  less  effective  than  chemical 
extinguishers,  because  their  contents  cannot 
be  propelled  as  accurately  or  as  far.  Fire 
pails  should  be  painted  red  so  that  they 
can  be  identified  if  thoughtlessly  removed 
from  their  accustomed  places  for  othei 
service.  They  should  always  remain  in  the 
FIG.  46. — Section  same  conspicuous  and  convenient  places,  and 

through  portable  fire    care  shOuld  be  taken  to  prevent  their  contents 
extinguisher.  . 

from  freezing.     The  pails  should  be  inspected 

frequently  as   a   safeguard   against  leakage    and    evaporation. 
The  value  of  fire  pails  has  been  described  as  follows  :2 

A  pail  of  water  is  the  best  fire  extinguisher  yet  devised.  It  costs 
little;  its  use  is  understood  by  everyone;  it  is  easily  kept  ready  for  use; 
and  its  effect,  if  used  at  the  proper  moment,  may  be  better  than  the  work 
of  an  entire  fire  department  five  minutes  later.  The  value  of  fire  pails 
has  come  to  be  recognized,  not  only  by  the  insurance  community  and 
by  practical  firemen,  but  also  by  all  other  persons  having  a  care  for  the 
safety  of  life  and  property.  Accordingly,  it  is  a  common  practice  for 
property  owners,  of  their  own  accord,  to  have  pails  of  water  ready,  in 

1  The  directions  that  appear  upon  extinguishers  of  a  certain  approved  type 
are  as  follows:  "Fill  the  receptacle  with  two  and  one-half  gallons  of  water, 
add  two  and  one-half  pounds  bicarbonate  soda;  stir  well  to  dissolve.     Fill 
to  acid  line  with  four  fluid  ounces  of  sulphuric  acid  and  place  stopper  in 
bottle,  and  bottle  in  cage.     Screw  cap  down  tight.     Protect  from  freezing. 
If  i  used,   clean  well  and  recharge.     Discharge,   clean  well  and  recharge 
yearly.     Record  date  when  charged."     See  also  "Requirements  for  Proper 
Installation  Chemical  Fire  Extinguishers"  (Published  by  New  York  Fire 
Insurance  Exchange,  1913). 

2  " Requirements  for  Proper  Installation  of  Fire  Pails"   (Published  by 
The  New  York  Fire  Insurance  Exchange,  1909). 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  291 

case  of  fire;  in  addition,  the  officers  of  local  fire  departments  use  their 
authority  to  bring  this  about,  and  fire  insurance  organizations  have  not 
been  lacking  in  encouraging  the  insuring  public  to  equip  their  premises 
with  this  simple  means  of  fire  protection. 

The  New  York  Fire  Insurance  Exchange,  in  common  with  other  in- 
surance organizations,  has  placed  a  premium  on  fire-pail  equipments  by 
granting  a  liberal  reduction  in  rates,  where  the  premises  of  an  assured  con- 
tain fire  pails,  maintained  in  a  manner  which  assures  a  fair  probability 
of  their  being  ready  for  use  when  needed.  Fire  pails  are  useful  only 
when  they  are  filled,  within  easy  reach,  and  near  at  hand;  and  in  order 
to  provide  some  guarantee  of  efficiency,  the  fire  insurance  community 
has  been  obliged  to  adopt  certain  rules  regarding  fire  pails,  and  to  make 
a  proper  observance  of  these  rules  a  condition  to  granting  the  reduction 
in  rates.  These  and  similar  fire  insurance  rules  are  the  result  of  more 
than  fifty  years'  experience  with  the  insuring  public,  who,  with  the  best 
of  intentions,  frequently  install  costly  fire  protection  equipments,and  then 
take  no  steps  toward  keeping  them  in  condition  for  use  when  fire  occurs. 

In  the  case  of  fire  pails,  for  example,  it  has  been  found  advisable  to 
require  that  the  pails  be  painted  red,  with  the  word  "FIRE"  or  "FOR 
FIRE  ONLY"  in  black  letters  of  a  certain  size.  The  red  color  is  useful 
because  of  its  general  association  with  fire;  it  helps  to  make  the  pail 
clearly  visible  when  wanted;  and,  with  the  word  "FIRE,"  is  a  constant 
reminder  that  the  pail  is  there  for  a  special  purpose,  the  putting  out  of 
fire,  and  is  not  to  be  taken  away  or  used  for  ordinary  purposes.  The 
placing  at  a  medium  height  is  devised  to  permit  of  grasping  the  pail  with- 
out spilling  half  its  contents;  if  a  pail  is  placed  more  than  five  feet  high, 
it  is  likely  to  be  out  of  the  reach  of  the  average  person;  and  if  set  lower 
than  two  feet,  it  is  likely  to  be  overlooked  or  to  be  knocked  from  its 
position.  The  use  of  an  iron  pail  in  preference  to  a  pail  of  wood  or  other 
material,  is  a  matter  of  service  and  economy,  in  addition  to  the  greater 
likelihood  that  an  iron  pail  will  be  found  serviceable  when  suddenly 
wanted  for  use.  The  requirement  of  a  stated  number  distributed  in 
groups  throughout  the  entire  premises,  is  framed  to  provide  that  pails 
shall  be  within  a  hand's  grasp,  and  not  be  distant  anywhere  from  50 
to  200  feet  at  a  time  when  a  tiny  flame  is  rapidly  growing  into  a  formid- 
able blaze.  The  insistence  of  a  permanent  setting,  such  as  hooks  or 
shelves,  is  intended  to  make  sure  that  the  pail  will  be  given  a  fixed  posi- 
tion, which  will  become  familiar  to  the  occupants  who,  in  time  of  excite- 
ment, can  rely  on  finding  pails  in  a  definite  spot.  The  regular  re-filling 
is  a  common-sense  precaution  to  make  sure  that  the  pails  shall  contain 
water.  Such  rules  as  these  are  part  of  the  usual  discipline  maintained 
in  establishments  which  have  in  view  a  careful  management  of  the 
property,  and  they  are  published  in  the  belief  that  a  proper  observance 
of  them  will  tend  to  reduce  the  loss  suffered  by  the  community  from  the 
effects  of  fire. 


292  ORGANIC  STRUCTURAL  MATERIALS 

When  fire  pails  are  located  where  there  is  a  liability  of  the  water 
being  frozen  in  cold  weather,  it  is  recommended  that  2  pounds  of  chloride 
of  calcium  or  salt  (the  chloride  of  calcium  is  preferable),  be  placed  in 
each  pail.  For  casks  the  quantity  recommended  is  fifty  pounds  for 
each  cask.  It  is  necessary  that  the  chloride  of  calcium  or  the  salt  be 
dissolved  by  thorough  stirring. 

Organization. — It  should  be  remembered  that  fire  losses  are 
caused  by  failure  and  the  misuse  of  apparatus  as  well  as  by  its 
absence.  The  efficiency  of  the  best  apparatus  is  limited  by  the 
way  in  which  it  is  used,  and,  for  this  reason,  the  highest  efficiency 
is  seldom  obtained  outside  of  large  cities  where  there  are  paid 
fire  departments.  The  danger  from  fire  is  less  where  those  in 
charge  of  apparatus  are  taught  how  to  use  it  before  an  actual 
emergency  takes  place.  A  plan  of  action  should  be  formed  and 
all  details  be  considered  before  a  fire  takes  place. 

SOME  PRINCIPLES  OF  FIRE  PROTECTION 

•  For  completeness  some  space  is  given  to  the  general  field  of 
Fire  Protection. 

It  was  stated  that  the  policy  in  Europe  is  to  prevent  fires,  but 
that  in  this  country,  until  recently,  the  principal  demand  has 
been  for  means  to  extinguish  them,  and  that  this  difference 
explains  why  losses  are  so  much  greater  in  this  country  than  in 
others.  Fires  may  be  prevented  by  eliminating  the  factors  that 
are  known  to  cause  them,  one  of  which  is  wood. 

One  reason  why  preventive  practices  are  emphasized  in 
foreign  countries  is  because  wood  is  less  plentiful  in  such  coun- 
tries. These  practices  were  not  introduced  suddenly,  but  grew, 
little  by  little,  as  local  supplies  of  wood  gradually  decreased. 
It  was  the  law  of  necessity  that,  in  Europe,  caused  the  substitu- 
tion of  non-inflammable  materials  for  wood,  and  already  the 
same  law  is  beginning  to  serve  similarly  in  the  United  States. 

The  conditions  in  Europe  and  in  this  country  differ  in  that 
larger  proportions  of  what  may  be  called  " final  constructions" 
exist  abroad  where  civilization  is  older.  That  which  is  regarded 
as  mere  neglect  or  misfortune  here,  is  considered  there  more  as 
though  it  were  a  crime.  The  police  in  Berlin  have  very  real 
authority  over  every  detail  that  is  likely  to  increase  danger 
from  fires,  while  citizens  of  France  are  held  legally  responsible  for 
fires  that  pass  from  their  own  homes  to  those  of  others: 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  293 

Preventive  practices  in  the  United  States  had  their  origin  in 
the  factory  districts  of  New  England,  and  some  of  the  best  and 
most  modern  details  in  this  field  have  been  evolved  by  manu- 
facturers in  those  sections.  The  National  Fire  Protection  Asso- 
ciation, the  National  Board  of  Fire  Underwriters,  Factory  Mu- 
tuals,  and  other  organizations  now  exist  to  study  causes  and 
suggest  methods  by  which  fires  may  be  prevented. 

The  organizations  alluded  to  occupy  a  field  in  this  country 
that  suggests  the  one  occupied  by  paternal  governments  abroad. 
Very  much  has  been  accomplished  by  them  already,  but  improve- 
ment to  the  point  of  the  average  conditions  that  exist  in  older 
countries  cannot  be  hoped  for  for  some  time  to  come.  Many 
structures  that  were  erected  to  meet  first  needs  in  the  United 
States  have  already  given  way  to  others,  better  and  more  per- 
manent, but  much  remains  to  be  done.  The  rebuilding  of  a 
country  is  a  very  slow  process. 

It  will  be  remembered  that  the  preceding  section  was  devoted 
to  a  study  of  the  material  Wood  when  burning,  and  that  the  text 
was  presented  under  the  titles  "Burning  of  Wood,"  "Attempts 
to  Prevent  Wood  from  Burning,"  and  "Methods  Used  to  Extin- 
guish Burning  Wood."  As  distinct  from  this,  the  subject  of 
Fire  Protection  is  devoted  to  a  study  of  burning  Buildings  and 
the  parts  of  this  subject  will  be  grouped  as  they  relate  to  (1) 
"Burning  of  Buildings,"  and  (2)  "Method  by  which  Buildings 
are  Prevented  from  Burning." 

Burning  Buildings. — Such  fires  may  be  classified  as  they 
originate  within  the  buildings,  or  as  they  are  transferred  from 
without.  The  latter  are  known  as  "exposure  fires,"  and  a  large 
proportion  of  the  destruction  that  takes  place  in  this  country  is 
of  this  type. 

The  superiority  of  the  average  European  building,  from  the 
fire  standpoint,  is  shown  by  the  fact  that  a  larger  proportion  of 
the  fires  in  Europe  are  confined  to  the  buildings  in  which  they 
start.  Aside  from  fires  due  to  warfare,  the  great  conflagrations 
that  have  taken  place  in  all  Europe  during  several  centuries  have 
destroyed  less  property  than  those  that  have  taken  place  in  the 
United  States  alone  during  a  single  century. 

The  destructive  temperatures  in  burning  buildings  vary 
between  1,500  degrees  Fahrenheit  and  perhaps  2,500  degrees 
Fahrenheit.  Drafts  and  air  currents  must  also  be  considered. 
Materials  may  be  injured  not  only  by  heat,  but,  also  by  sudden 


294  ORGANIC  STRUCTURAL  MATERIALS 

cooling,  as  when  streams  of  water  are  applied  to  them  suddenly 
while  they  are  hot. 

Methods  By  Which  Buildings  Are  Prevented  From  Burning. 
—It  is  doubtless  true  that  in  the  United  States  some  general 
fires  have  been  prevented  by  the  presence  of  parks,  streets,  and 
other  open  spaces,  and  by  the  moderate  heights  of  structures; 
but  great  fires,  that  have  few  counterparts  in  European  history, 
have  taken  place  in  Portland,  New  York,  Chicago,  Boston, 
Jacksonville,  Paterson,  Baltimore,  San  Francisco,  and  Chelsea. 

The  first  real  attempts  to  reduce  fire  losses  came  when  brick 
and  stone  were  used  instead  of  wood  for  outside  walls.  Walls  of 
brick  and  stone  were  made  to  support  floors  and  roofs  of  wood, 
and  buildings  of  this  kind  resisted  better  than  those  of  the  earlier 
type,  because  they  offered  more  resistance  to  outside  fires.1 

Later  attempts  included  the  use  of  iron  and  steel,  but  these 
materials  were  not  protected  as  they  are  at  the  present  time. 
The  high  conductivity  of  iron  and  steel,  and  their  tendency  to 
expand  under  comparatively  small  increases  of  temperature 
caused  these  unprotected  beams  and  columns  to  bend  and  collapse 
even  in  very  small  fires.  Buildings  constructed  in  this  manner 
were  but  little  better  than  those  of  wood. 

Buildings  are  now  designed  to  stand  against  both  inside  and 
outside  fires.  A  fire  may  destroy  the  inflammable  contents  in  a 
room  or  other  section  of  such  a  building,  but  it  will  not  normally 
reach  over  into  another  room  or  section  of  the  building.  Details 
relating  to  materials,  design,  special  devices  and  the  care  of  the 
buildings  after  they  are  erected  are  all  important.  It  should  be 
constantly  remembered  that  the  building  may  be  strictly  fire- 
proof but  that  its  contents,  as  distinct  from  the  building  itself, 
may  be  inflammable,  and  that  such  contents,  if  too  great  in 
quantity,  may  cause  the  destruction  of  the  building. 

Materials. — It  is  obvious  that  the  best  way  to  prevent  a  structure 
from  burning  is  to  build  it  of  something  that  will  not  burn.  Yet  it 
must  be  remembered  that  some  materials  that  do  not  burn  are  not  to 
be  regarded  as  fireproof.  A  really  fireproof  material  will  not  only  resist 
the  disintegrating  and  distorting  influences  due  to  high  heat  and  sudden 
cooling,  but  it  will  not  conduct  heat. 

1  $68,000,000  of  the  total  loss  in  the  United  States  in  1907  took  place  in 
buildings  composed  of  brick,  concrete,  stone,  and  similar  materials;  while 
the  loss  in  wooden  buildings  during  the  same  year  was  over  twice  as  much, 
or  about  $148,000,000. 


WOOD  AN  AGENT  IN  CONFLAGRATIONS 


295 


FIG.  47.— 


Metals. — Iron  and  steel  are  poor  fireproof  materials  when  used  alone. 
This  is  because  they  warp  and  conduct  heat,  and  it  is  only  after  they 
are  protected  by  non-conducting  substances  that  they  become  valuable 
in  fireproof  constructions. 

Natural  Stones. — Stones  differ  greatly  in  their  ability  to  stand  against 
heat.  Granites  disintegrate  because  they  contain  water,  and  because 
the  component  minerals  do  not  have  the  same  coefficients  of  expansion 
and  contraction  under  heat  and  cold.  Limestones  lose  their  carbon  diox- 
ide and  are  reduced  to  ordinary  building  lime  under  the  influence  of 
heat.  Most  sandstones  stand  against  fire  better  than  all  limestones, 
and  far  better  than  all  granites. 

Artificial  Stones. — The  prop- 
erties of  brick  are  influenced 
by  the  properties  of  the  clays 
used  in  their  manufacture. 
Good  brick  is  one  of  the  best 
of  all  fireproof  materials. 
Enamelled  brick  is  often 
very  good.  Terra  cotta, 
whether  used  in  bricks,  or 
for  ornamental  work,  or  as  a 
protective  coating  for  iron 
and  steel,  is  a  very  valuable 
fire-resisting  material.  Con- 
crete possesses  the  additional  advantage  that  it  can  be  laid  without 
joints. 

Combinations. — The  best  results  are  obtained  by  the  use  of  all-metal 
members  protected  by  brick,  terra  cotta,  concrete,  or  other  non-con- 
ducting materials.  Hollow  brick,  terra  cotta,  and  concrete,  are  used 
for  walls,  floors,  and  ceilings. 

Influence  of  Design,  Special  Devices,  Etc. — An  ideal  building  has  out- 
side walls  of  brick.  Its  frame  is  made  of  steel  or  iron  covered  with  some 
material  that  will  stand  against  heat.  Floors  and  roofs  are  built  of 
hollow  tile,  terra  cotta,  concrete,  or  other  non-conducting  or  fire-resist- 
ing materials.  All  stairs,  elevators,  and  dumbwaiters  are  enclosed  by 
brick  shafts  with  standard,  tin-clad  fire  doors  in  all  openings.  Wells 
for  light  are  enclosed  by  brick,  and  the  windows  in  the  wells  are  of  wired 
glass  in  standard  metal  frames,  and  these  materials  are  also  used  in 
outside  windows.  Standard  fire  doors,  or  their  equivalents,  are  used 
in  door  openings.  A  low  building  is  safer  than  a  high  building.  An  ideal 
building  is  restricted  in  height  and  floor  areas  so  that  all  parts  can  be 
swept  by  fire  streams  under  prevailing  pressures.  Heights  and  areas  can 
be  increased  if  the  entire  building  is  protected  by  automatic  sprinklers. 

Roofs. — Roofs  are  either  fireproof,  semi-fireproof,  or  inflammable. 
Roofs  covered  with  slate,  tile,  and  some  special  materials  are  in  the  first 


;e  protected  by  duplicate 
re  doors. 


296  ORGANIC  STRUCTURAL  MATERIALS 

group;  while  those  made  of  tin  or  corrugated  iron  spread  upon  wood 
are  in  the  second  group.  Shingled  roofs,  which  are  in  the  third  group, 
are  highly  inflammable.  A  large  proportion  of  all  outside  fires  are  caused 
by  sparks  lodging  on  roofs. 

Door  Openings. — Fire  doors,  designed  to  obstruct  the  passage  of  heat 
and  flame  through  door  openings,  are  used  in  pairs,  one  door  being 
placed  at  each  one  of  the  two  surfaces  of  the  wall  through  which  the 
opening  extends.  Automatic  doors,  that  close  when  the  heat  becomes 
sufficient  to  fuse  a  link  of  special  metal,  are  generally  recommended. 
Latches,  locks,  hinges,  slides,  and  other  details  are  highly  important. 
The  efficiency  of  the  standard  fire  door  is  expressed  in  the  following 
quotation.1  "  Recent  tests  and  investigations  indicate  that  for  openings 
of  ordinary  size  the  so-called  standard  tin-clad  door  and  shutter,  all 
things  considered,  furnishes  the  most  reliable  protection,  particularly 
when  the  exposures  are  severe.  The  superiority  of  this  type  is  very 
largely  due  to  its  efficiency  as  a  non-conductor  of  heat.  This  offsets,  in 
a  large  measure,  inherent  defects  in  other  respects,  such  as  the  bulging 
of  the  plates  by  the  gases  generated  from  the  inflammable  materials 
now  used  in  its  construction,  the  falling  down  of  the  core  after  it  has 
been  reduced  to  charcoal,  and  its  comparative  lack  of  endurance  under 
severe  exposures." 

Window  Openings. — Water  curtains  and  iron  shutters  were  formerly 
used  to  protect  window  openings,  but  these  devices  have  given  way  to 
standard  fire  shutters,  and  wired  glass  windows.  Tin-clad  fire  shutters 
are  similar  to  the  standard  fire  doors  that  have  been  described;  while 
the  wired  glass  is  used,  as  has  been  noted,  in  metal  frames.  The  re- 
quirements of  both  inside  and  exposed  fires  must  be  recognized. 

The  value  of  wired  glass  windows  in  resisting  the  action  of  moderate 
fires  depends  upon  the  character  of  the  glass  and  sashes.  Glass  softens 
and  drops  away  when  a  temperature  of  about  1,500  degrees  F.  is  reached. 
Sashes  and  frames  are  made  of  hollow  steel  and  other  metal.  There  are 
three  types :  the  pivoted  sash,  which  is  automatic,  the  double  hung  sash, 
and  the  casement  sash.  Locks,  hinges,  and  other  hardware  are  im- 
portant factors.  Ordinary  putty  must  not  be  used.2 

Fire  Shutters. — The  principal  difference  between  fire  shutters  and 
fire  doors  is  noted  in  the  rules  prepared  by  the  National  Board  of  Fire 

1  Abstract  of  Committee  Report  presented  at  annual  meeting  of  National 
Fire  Protection  Association,  New  York  City,  May  23-25,  1905  (Engineering 
News,  Vol.  53,  No.  22).     Also  Rules  and  Requirements  for  the  Construction 
and  Installation  of  Fire  Doors  and  Shutters  recommended  by  the  National 
Fire  Protection  Association  (Edition  of  1906). 

2  Rules  and  Requirements  of  the  National  Board  of  Fire  Underwriters  for 
the  Manufacture  of  Wired  Glass  and  the  Construction  of  Frames  for  Wired 
and  Prism  Glass  used  as  a  Fire  Retardant. 


PLATE  VIII.    DETAILS  OF  TIN-CLAD  FIRE  DOOR 


-J-T- 

^r-r 


(c)   Method  of  Joining  and  Fastening 
Tin. 


(a)  Application  of 
Tin  to  Corners  of  Fire 
Door. 


(6)  Method  of  Holding 
Layers  of  Core  together 
by  Clinched  Nails. 


(d)  The  Completed  Door. 

(Facing  page  296.) 


WOOD  AN  AGENT  IN  CONFLAGRATIONS 


297 


Ell— J 


Underwriters  as  follows:1  " Construction  to  be  the  same  as  for  fire  doors, 
except  that  only  two  thicknesses  of  %  inch  boards  are  required.  Layers 
of  boards  to  be  at  right  angles." 

Automatic  Sprinklers. — It  is  a  important  to  have  fires  discovered  and 
extinguished  while  they  are  small,  and  apparatus  Designed  with  these 
ends  in  view  may  be  properly  classed  among  prevent ative  devices. 

General  information  with  respect  to  automatic  and  open  sprinkler 
equipments,  prepared  by  the  National  Board  of  Fire  Underwriters,  is 
as  follows :  2 

1.  Preparation  of  Building. — Many  buildings  require  preparation  for 
sprinkler   equipment.     All  needless 

ceiling  sheathing,  hollow  siding,  tops 
of  high  shelving,  needless  partitions  or 
decks  should  be  removed.  Necessary 
" stops"  to  check  draft,  necessary  new 
partitions,  closets,  decks,  etc.,  should 
be  put  in  place  so  that  the  equipment 
may  conform  to  the  same.  The  top 
flooring  should  be  made  thoroughly 
tight. 

2.  Accessory     Woodwork. — Sprinkler 
equipments    require    accessory  wood- 
work, dry  pipe  valve  closets,  ladders, 
anti-freezing  boxing  for  tank  pipes,  etc. 
This   work  should  be   promptly   at- 
tended   to   if  not   let   with    sprinkler 
contract. 

3.  Drapery  and  Sheathing. — Paper  or  similar  light  inflammable  ceiling 
sheathing  is  objectionable  and  unnecessary.     Where  floors  leak  dirt,  an 
acceptable  sheathing  may  be  made  of  lath  and  plaster,  matched  boards 
or  joined  metal.     All  channels  back  of  sheathing  to  be  thoroughly  closed 
between  timbers  or  joists.     Sheathing  to  be  tightly  put  together  and 
kept  in  repair.     In  mill  bays,  sheathing  to  follow  contour  of  timbers 
without  concealed  space. 

1  Rules  and  Requirements  for  the  Construction  and  Installation  of  Fire 
Doors  and  Shutters  as  recommended  by  the   National  Fire  Protection 
Association  (Edition  of  1906). 

2  Rules  and  Requirements  National  Board  of  Fire  Underwriters  governing 
the  Installation  of  Automatic  and  Open  Sprinkler  Equipments  as  recom- 
mended by  the  National  Fire  Protection  Association  (Edition  of  1913). 

3  This  window  was  in  Newark  works  of  Sherwin-Williams  Company. 
The  picture  shows  appearance  after  fire  had  destroyed  adjacent  works  of 
Consolidated    Color    and    Chemical    Company.     The   fire   did    not    pass 
through  this  window,  although  the  heat  was  sufficient  to  burn  the  paint 
from  frame  and  sash  (Insurance  Engineering,  November,  1907). 


FIG.  48. — Wired  glass  window 
in  metal  sash. 3 


298  ORGANIC  STRUCTURAL  MATERIALS 

4.  Vertical  or  Horizontal  Drafts. — Floor  or  wall  openings  tending  to 
create  vertical  or  horizontal  drafts,  or  other  structural  defects  that 
would  prevent  the  prompt  operation  of  automatic  sprinklers  by  prevent- 
ing the  banking  up  of  the  heated  air  from  the  fire,  should  -be  properly 
"stopped"  in  order  to  permit  specific  control  by  the  local  sprinklers. 
Satisfactory  curtain-boards  and  other  draft-stops  must  be  provided  to 
overcome  such  structural  defects. 

5.  Clear  Space  Below  Ceilings. — Full  effective  action  of  sprinklers  re- 
quires about  24  inches  wholly  clear  space  below  roofs  or  ceilings;  this 
loss  of  storage  capacity  should  be  realized  in  advance  of  equipment. 

6.  Experienced  Workmen  Recommended. — Sprinkler  installation  is  a 
trade  in  itself.     Insurance  inspectors  cannot  be  expected  to  act  as  work- 
ing superintendents,  nor  correct  errors  of  beginners.     Sprinkler  work 
should  be  entrusted  to  none  but  fully  experienced  and  responsible  parties. 

7.  All  Portions  of  Buildings  to  be  Protected. — Experience  teaches  that 
sprinklers  are  often  necessary  where  seemingly  least  needed.     Their 
protection  is  required  not  alone  where  a  fire  may  begin,  but  also  wherever 
any  fire  might  extend,  including  wet  or  damp  locations. 

8.  Degree  of  Protection. — A  maximum  protection  cannot  be  expected 
where  sprinklers  are  at  more  or  less  permanent  disadvantage,  as  in  the 
case  of  stocks  very  susceptible  to  smoke  and  water  damage,  buildings 
having  deep  piles  of  hollow  goods,  excessive  drafts,  explosion  or  flash 
fire  hazards,  or  large  amounts  of  benzine  or  similar  fluid. 

9.  Necessary  Cut-offs. — Sprinklers  cannot  be  expected  to  keep  out  fire 
originating  in  unsprinklered  territory.     Stringent  measures  should  be 
used  to  properly  cut  off  all  unsprinklered  portions  of  buildings  or 
exposures. 

10.  Communications. — When  a  building  fully  equipped  with  sprink- 
lers communicates  with  another  not  so  equipped,  the  openings  must  be 
protected  by  standard  fire  doors  on  both  sides  of  the  walls,  one  of  which 
must  be  automatic. 

11.  Protection  Against  Exposures. — The  danger  of  sprinkler  protection 
being  impaired    by  exposure  fires  should   be  reduced   by  providing 
adequate  shutters,  wired  glass  or  open  sprinkler  protection  at  exposed 
windows. 

Signals. — There  are  automatic  and  non-automatic  signals.  An  auto- 
matic thermostat  alarm  depends  upon  the  opening  and  shutting  of  an 
electric  circuit  in  a  thermostat.  Such  alarms  are  used  in  connection 
with  automatic  sprinklers.  Non-automatic  alarms  should  be  practical, 
conveniently  located,  and  easily  understood. 

Care  or  Maintenance  of  Structures. — The  contents  of  a  building  are 
as  important  as  the  building  itself.  The  building  may  be  composed  of 
materials  that  will  not  burn,  yet  it  may  be  injured  or  even  destroyed 
by  fires  in  contained  oils,  cotton,  or  similar  stores.  The  quantity  of 
such  inflammable  stores  should  always  accord  with  the  capacity  of  the 


WOOD  AN  AGENT  IN  CONFLAGRATIONS  299 

building  to  resist  fires  and  with  its  capacity  to  isolate  them  so  that  they 
will  not  spread  from  one  section  to  another. 

Cleanliness  and  Order  Are  Imperative. — Trash  should  not  be  permitted 
to  accumulate.  Oiled  rags  or  waste  should  be  destroyed,  or  kept  in 
metal  boxes.  Matches  should  also  be  stored  in  metal  boxes.  Smoking 
must  often  be  prohibited.  Systematic  inspection  is  usually  necessary. 
Managers  should  be  held  responsible  by  night  as  well  as  by  day.  It  is 
not  enough  for  them  to  employ  watchmen.  They  should  be  certain 
that  such  assistants,  who  are  usually  selected  for  physical  rather  than 
mental  gifts,  really  perform  their  duties.  Watchmen  work  alone  and 
without  direct  superintendence,  and,  for  this  reason,  their  duties  should 
be  planned  for  them. 

Watchmen's  Recorders. — The  services  of  watchmen  are  systematized 
by  means  of  mechanical  devices  known  as  recorders  that  compel  the 
watchmen  to  visit  certain  stations  at  certain  stated  intervals.  These 
recorders  are  of  three  kinds.  There  are  portable  time  recorders,  station- 
ary time  recorders,  and  central  office  recorders.1 

Portable  Time  Recorders. — The  recorder  resembles  an  alarm  clock  and 
contains  a  paper  dial,  turned  by  clock  movement,  upon  which  an  impres- 
sion is  made  whenever  a  key  is  used.  There  are  several  such  keys,  with 
but  one  recorder,  which  last  is  carried  by  the  watchman,  while  the  keys 
are  chained  at  the  several  stations  to  be  visited.  The  records  shown 
by  the  paper  dials  indicate  the  time  when  each  key  was  used.  This 
system  is  simple  and  economical  in  its  first  cost,  but  it  is  objectionable 
because  of  the  weight  of  the  recorder  and  because  of  the  fact  that  watch- 
men sometimes  obtain  duplicate  keys. 

Stationary  Time  Recorders. — In  this  system  there  is  one  key  and  sev- 
eral recorders.  The  watchman  carries  the  key  and  the  recorders  are 
fixed  at  the  stations.  Some  recorders  contain  paper  record  forms  which 
are  collected  in  the  morning,  and  others  are  wired  so  that  the  records 
are  received  on  a  single  dial  in  the  superintendent's  office.  A  stationary 
time  recorder  system  is  good  because  watchmen  do  not  have  to  carry 
the  more  or  less  heavy  recorders,  and  because  it  is  difficult  to  tamper 
with  the  records.  The  weak  points  are  the  increased  first  cost,  and  the 
labor  required  to  collect  the  records  in  the  morning.  When  such  labor 
is  rendered  unnecessary  by  connecting  the  recorders  with  the  superin- 
tendent's office,  there  is  extra  cost  for  wiring. 

Central  Office  Systems. — The  central  office  system  enables  a  superin- 
tendent, located  at  a  central  office,  to  reach  and  control  the  movements 
of  his  men  at  all  times  while  they  are  on  duty. 

1  New  York  Fire  Insurance  Exchange  Bulletin,  No.  5.  Also  literature 
published  by  Newman  Portable  Clock  Company,  American  Watch  System, 
etc.,  etc. 


CHAPTER  XII 

FAILURE  OF  WOOD  BECAUSE  OF  ANIMAL  LIFE.     MARINE  AND 
TERRESTRIAL  FORMS.     METHODS  OF  PROTECTION 

The  forms  of  animal  life  that  attack  woods  may  be  divided 
according  to  their  habits  or  environment  into  marine  woodborers1 
and  terrestrial  woodborers. 

The  quantity  of  wood  destroyed  by  marine  woodborers  is 
considerable,  but  the  proportion  is  much  smaller  than  it  was 
when  wood  was  used  more  extensively  in  marine  constructions. 
The  total  value  of  wood  destroyed  by  marine  borers  is  much  less 
than  the  total  value  of  woods  and  living  trees  destroyed  by 
terrestrial  borers. 

MARINE  WOODBORERS 

The  harm  done  by  these  borers  has  not  always  been  measur- 
able by  direct  costs,  since  it  is  recorded  that  owners  of  wooden 
ships  once  discriminated  against  harbors  in  which  numbers  of 
these  pests  were  known  to  be -present. 

Most .  perforations  found  in  timbers  that  have  been  in  sea 
water  are  attributed  to  the  Teredo  navalis,  probably  because 
this  shipworm  was  one  of  the  first  to  be  studied  and  was  the  one 
selected  for  description  in  some  of  the  earlier  text-books.  The 
Teredo  navalis  is  worthy  of  the  attention  it  receives,  but  it  must 
not  be  forgotten  that  there  are  other  marine  woodborers. 

THE  SHIPWORM  (Teredo,  Xylotrya,  etc.).— This  is  a  general 
name  that  applies  to  several  species  of  mollusks  of  the  genus 
Teredo,  together  with  other  species  in  other  genera.  The  mol- 
lusks known  as  shipworms  are  characterized  by  the  fact  that  they 
bore  in  wood,  and  are  represented,  along  the  north-central  Atlantic 
Coast,  by  species  of  the  genus  Xylotrya. 

Shipworms  are  widely  distributed  throughout  the  waters  of 
the  tropics,  and  are  present  in  smaller  numbers  in  cooler  waters  of 
temperate  regions.  They  inhabit  European  waters  from  Sweden 

1  The  first  part  of  this  chapter  is  based  upon  the  author's  paper  entitled 
"Marine  Woodborers"  published  by  the  American  Society  of  Civil  Engi- 
neers (Transactions,  Vol.  XL,  1898).  Some  of  the  pictures  prepared  for  the 
original  paper  are  used  with  the  permission  of  the  said  Society. 

300 


MARINE  AND  TERRESTRIAL  WOODBORERS  301 

to  Sicily,  and  are  also  found  in  the  vicinity  of  Bermuda,  the  West 
Indies,  New  Zealand,  and  Australia.  In  the  United  States  they 
exist  from  Maine  to  Florida,  and  along  the  Pacific  Coast  as  far 
north  as  Alaska.  The  United  States  Fish  Commission  reports 
their  distribution  in  local  waters  to  be  as  follows : 

Teredo  navalis,  between  Florida  and  Cape  Cod.  Teredo  norvegica, 
Cape  Cod  northward  to  Maine.  Teredo  megotara,  New  Bedford,  south 
to  South  Carolina.  Teredo  dilatata,  Massachusetts  to  South  Carolina. 
Teredo  thompsoni,  Massachusetts.  Xylophaga  dorsalis,  North  Atlan- 
tic. Xylotrya  fimbriata,  Long  Island  Sound  to  Florida. 

Form. — The  form  of  the  shipworm  is  shown  in  the  picture. 
It  is  a  long,  worm-like  organism  of  which  the  posterior  end  s 
remains  at  the  outer  surface  of 
the  timber,  while  the  other  or 
anterior  end  B  occupies  the 
inner  extremity  of  the  tunnel. 
The  two  horn-shaped  structures 
s  are  the  free  extremities  of  other- 
wise united  tubes,  known  as 

siphons,   that    pass   throughout  FlG   49._The  shipworm. 

the  entire  length  of  the  ship- 
worm  to  the  vital  organs  and  boring  shell  at  B.  These  horn- 
shaped  extremities  are  the  only  parts  of  the  shipworm  that  can 
extend  outward  beyond  the  wood,  and  are  therefore  the  only 
parts  that  are  evident  to  the  casual  observer. 

A  general  idea  of  the  form  of  the  shipworm  may  be  gained  by 
examining  the  ordinary  long,  or  soft-shelled,  clam  (Mya  arenaria) 
so  familiar  to  residents  of  New  England.  This  clam  possesses  a 
very  long  worm-like  neck  penetrated  by  two  parallel  tubes  or 
siphons  through  one  of  which  water,  oxygen,  and  food  pass  in- 
ward, while  through  the  other  exhausted  water  and  debris  pass 
out.  It  is  also  helpful  to  examine  the  common  razor  clam  (Ensis 
directus)  which,  besides  siphons,  possesses  a  powerful,  muscular 
club-shaped  foot  or  sucker  that  enables  it  to  bore  into  the  sand. 
The  long  and  razor  clams  and  the  shipworm  are  all  true  mollusks, 
and  each  one  suggests  a  worm  only  because  the  part  that  sur- 
rounds the  siphons  is  soft  and  cylindrical. 

The  parts  of  the  shipworm  that  are  important  in  the  present 
connection  are  the  body,  siphons,  collar,  pallets,  boring  shell, 
foot,  and  lining  shell.  These  parts  will  be  considered  separately. 


302 


ORGANIC  STRUCTURAL  MATERIALS 


The  Body.  —  The  translucent  substance  of  which  the  body  is  composed 
resembles  the  living  substance  in  the  body  of  the  oyster.  In  some 
species,  in  addition  to  their  normal  functions  of  respiration,  the  gills 
perform  the  important  office  of  sheltering  the  embryo.  The  nervous 
system  is  well  developed.  Vital  organs,  such  as  the  liver,  are  protected 
by  being  enclosed  within  the  boring  shell.  The  stomach  is  not  distin- 
guished by  any  peculiarity.  There  is  a  long  intestine.1 

The  Siphons.  —  The  siphons  extend  through  almost  the  entire  length 
of  the  body.  One  of  them  conveys  the  oxygen,  water,  and  infusorial 

food  to  the  digestive  organs; 
while  the  other  conveys  the  ex- 
hausted water,  excretions,  and 
wood  particles  from  the  excavation 
to  the  free  water  without. 

The  siphons  are  joined  together 
for  most  of  their  length,  but  separate 
as  they  pass  outward  at  their 
extremities,  s,  and  are  then*  capa- 
ble of  being  thrust  out  and  with- 
drawn through  the  orifice  in  the 
wood.  They  are  the  only  parts 
that  can  be  seen  from  the  outside 
of  the  wood.  It  will  be  noted  that 
these  extremities  must  always  re- 
™*  *  the  orifice  to  the  tunnel. 

When  the  conditions  are  favora- 
ble, the  extremities  of  the  siphons  are 

extended  out  to  their  full  length  beyond  the  surface  of  the  wood.  Other- 
wise, they  are  withdrawn  and  there  is  then  but  little  evidence  that  the 
shipworm  is  within  the  piece.  The  picture  shows  the  siphons  as  they 
appeared  fully  extended  after  several  consecutive  days  of  warm  weather. 
The  Collar.  —  The  collar  C  is  a  muscular,  wrinkled  membrane  that  ex- 
tends around  the  posterior  portion  of  the  shipworm  at  the  point  of  union 
between  the  siphon  and  the  body  proper,  and  forms 
a  connection  between  the  body  and  the  calcareous 
lining  of  the  tunnel.  This  is  the  only  place  at 
which  the  body  of  the  shipworm  is  not  free  and 
separated  from  its  surroundings.  The  collar  in- 
cludes .several  well-defined  muscles  and  these  act 
upon  the  small  shells  known  as  pallets  by  which  the  FlQ  51  _  pauets. 
entrance  to  the  perforation  may  be  guarded. 

The  Pallets.  —  The  two  shells  or  plates,  located  at  p  and  called  pallets, 
are  broad,  slightly  curved  and  flattened  at  the  top  and  contracted  at 


the  wood. 


Sigerfoos  (Circular  Johns  Hopkins  University,  June,  1896). 


PLATE  IX.    WORK  OF  THE  SHIPWORM 


Surface  of  Wood  recently  Occupied  by  Shipworms.     Life  Size. 


Section  Parallel  to  Face  Shown  in  Preceding  Figure.     Life  Size. 


Vertical  Section  through  Preceding  Figures.     Life  Size. 

(Facing  page  302.) 


MARINE  AND  TERRESTRIAL  WOODBORERS 


303 


the  bottom  where  they  pass  under  the  collar.  When  the  siphon  ex- 
tremities are  withdrawn  into  the  body,  the  tops  of  the  pallets  are  brought 
together  over  them  and  protect  them.  These  shells  are  sometimes  con- 
fused with  the  boring  shells,  which  are  quite  distinct,  and  at  the  other 
end  of  the  body.  Details  differ  with  species. 

The  Boring  Shell. — The  principal  or  boring  shell  B  is  small  and  very 
beautifully  formed.  The  two  parts  together  are  nearly  as  long  as  they 
are  broad,  and  present  an 
irregular  triangular  appear- 
ance when  observed  from 
the  side.  They  close  tightly 
at  the  hinge  and  at  the  side 
opposite.  As  distinct  from 
this,  however,  an  open  space 
at  the  top  permits  the  body 
to  emerge  while  a  similar 
opening  at  the  bottom  is  for 
the  foot  or  sucker.  The 
shells  of  young  shipworms 
are  much  larger  in  proportion 
than  those  of  older  ship- 
worms,  and  when  the  worm 
is  very  young,  it  is  for  a 
short  time  entirely  enclosed 
in  its  shell. 

The  Foot. — The  foot,  which  in  form  resembles  a  pestle,  is  a  short,  stout, 
muscular  organ,  broadly  truncated  or  rounded  at  the  end,  and  so  ar- 
ranged that  it  can  exert  a  powerful  suction  upon  anything  to  which  it 
is  attached.  The  extent  to  which  this  cupping  action  assists  the  exca- 
vating has  probably  been  underestimated. 

The  Calcareous  Lining. — Calcareous  material  deposited  upon  the 
woody  surface  of  the  tunnel  forms  a  smooth  lining  along  which  the  body 
of  the  shipworm  can  pass  as  it  contracts  or  expands.  This  shell-like 
tube  is  distinct  from  the  pallets  and  from  the  boring  shell.  Its  thick- 
ness, which  varies  with  species,  is  sometimes  so  slight  that  the  shell  is 
detached  by  the  slightest  shock,  and  many  specimens,  exhibited  in 
museums,  do  not  show  the  lining  for  this  reason.  The  lining  is  some- 
times very  thick.  The  shipworm  can  rarely  advance  through  the  wood 
very  far  in  a  straight  line,  but  is  forced  to  pass  here  and  there  so  as  to 
avoid  obstacles  such  as  cracks,  knots,  and  the  tunnels  of  its  companions. 
In  such  cases,  the  linings  are  curved  as  they  wind  in  and  out,  and 
often  so  many  are  present  that  almost  the  entire  content  of  the 
wood  is  occupied.  Shipworms  avoid  seams  and  joints  in  wood,  possibly 
because  of  their  effect  upon  the  calcareous  linings. 


FIG.  52.— The  boring  shell. 


304 


ORGANIC  STRUCTURAL  MATERIALS 


Physiology. — Shipworms  live  principally,  if  not  wholly,  upon 
organic  particles  obtained  from  sea  water.     Particles  of  wood  are 

sometimes  found  in  their  intestines, 
and  it  is  not  certain  that  these 
particles,  cut  from  the  burrows,  do 


FIG.  53. — End  view  of  dis- 
section shown  in  figure  which 
follows.  (Life  size.) 

not  serve  in  some  minor 
way  as  food.  It  is  certain, 
however,  that  the  principal 
reason  for  the  boring  is  to 
prepare  a  shelter. 

A  shipworm  can  live  for 
a  short  time  out  of  water. 
But,  since  it  derives  its  sus- 
tenance from  the  water,  it 
must  have  access  to  it  much 
of  the  time.  It  does  not 
have  to  be  submerged  all 
of  the  time,  and  can  live 
and  work  under  such  con- 
ditions as  exist  between 
tide  levels.  It  has  been 
known  to  live  for  about 
two  weeks  in  timbers  that 
have  been  transferred  from  the  sea  to  fresh  water,  and  could 
possibly  have  lived  longer  than  two  weeks. 


FIG.  54. — Dissection  showing   calcareous 
lining  in  wood.     (Life  size.) 


MARINE  AND  TERRESTRIAL  WOODBORERS  305 

Many  logs  in  a  cargo  of  Central  American  woods  recently  received 
in  New  York,  after  a  voyage  of  about  two  weeks,  were  found  to  be  full 
of  living  shipworms  that  had  gained  entrance  while  the  logs  were  waiting 
for  shipment  in  the  South.  The  shipworms  were  apparently  in  good 
condition  when  the  timbers  were  removed  from  the  hold  of  the  ship. 
The  wood  itself,  and  the  hold  of  the  ship,  contained  considerable  water, 
yet  the  logs  were  by  no  means  submerged,  and  the  fact  exists  that  these 
particular  specimens  survived  during  a  voyage  of  about  two  weeks. 
They  were  very  numerous,  so  much  so,  that  later  the  logs  had  to  be 
removed  from  the  yard  because  of  the  odor. 

Reproduction  and  Development. — Most  mollusks  reproduce  by 
means  of  eggs,  which,  in  the  case  of  some  shipworms,  are  spheri- 
cal in  shape  and  greenish  yellow  in  color.  Shipworms  are  very 
prolific,  the  eggs  of  a  single  specimen  being  numbered  by  the 
million.  The  eggs  are  very  hardy  and  many  survive  and  yield 
young  shipworms.  A  shipworm  can  swim  at  the  end  of  about 
three  hours  after  hatching  and  has  a  well-developed  shell  before 
the  end  of  the  first  day. 

The  shipworm  passes  through  several  stages  before  it  assumes 
the  character  and  form  of  the  adult.  It  is  first  covered  with  fine 
hairs  or  cilia,  which  enable  it  to  swim.  Soon  most  of  the  cilia 
are  lost  and  the  rudiments  of  a  small  bivalve  shell  appear.  At 
first,  this  shell  is  heart-shaped  and  very  small,  yet  it  is  large 
enough  to  enclose  almost  the  entire  body.  The  portion  of  the 
body  that  protrudes  from  the  cell  is  fringed  with  cilia,  and  these 
enable  it  to  continue  to  swim  until  it  finally  encounters  a  piece 
of  wood. 

The  results  of  some  observations  upon  the  shipworm  (Xylotrya 
fimbriata)  at  Beaufort  have  been  summarized  by  Professor 
Sigerfoos  as  follows:1 

"The  free-swimming  stage  is  reached  in  three  hours,  and  a  well- 
developed  shell  is  formed  in  a  day.  We  have  no  direct  observations  as 
to  the  time  the  ship  larva  is  free-swimming.  We  may  assume,  I  think, 
that  it  is  at  least  a  month,  or  it  may  be  two.  Most  of  its  energies  are 
devoted  to  locomotion  during  this  period,  but,  after  it  has  attached 
itself,  all  of  its  energies  are  devoted  to  forming  its  burrow  and  securing 
its  food.  Coming  into  contact  with  the  wood,  the  larva  throws  out  a  sin- 
gle, long  byssus  thread  for  attachment  and  never  again  leaves  its  place. 
The  newly  attached  larva  is  somewhat  less  than  0.25  mm.  long.  In 
twelve  days  it  has  attained  a  length  of  3  mm.;  in  sixteen  days,  6  mm.; 


Johns  Hopkins  Circular,  June, 


306  ORGANIC  STRUCTURAL  MATERIALS 

in  twenty  days,  11  mm.;  in  thirty  days,  63  mm.;  and  in  thirty-six  days, 
about  100  mm.,  when  it  bears  ripe  eggs  or  sperm." 

The  time  of  reproduction  is  important.  In  the  vicinity  of 
New  York,  this  takes  place  principally  during  the  month  of  May; 
but  it  may  continue,  although  to  a  less  extent,  throughout  the 
greater  part  of  the  summer.  In  tropical  countries,  it  probably 
goes  forward  throughout  the  entire  year.  Although  the  extreme 
life  limit  of  a  shipworm  is  unknown,  it  is  thought  that  individuals 
can  live  for  several  years  under  favorable  conditions.  A  ship- 
worm  may  attain  to  a  comparatively  large  size  during  a  single 
season. 

Influence  of  Temperature  and  Water. — In  most  cases  ship- 
worms  are  more  plentiful  where  the  water  is  not  cold,  and,  for 
this  reason,  wood  is  destroyed  more  continuously  and  more 
rapidly  in  the  tropics  and  semi-tropics.  In  the  United  States 
destruction  is  most  serious  along  the  entire  Pacific  Coast,  as 
well  as  along  the  coast  of  the  South  Atlantic  and  Gulf  States. 
Some  shipworms  are  found,  although  they  are  much  less  active, 
where  it  is  often  extremely  cold,  as  in  Maine  and  Alaska. 

Some  shipworms  thrive  in  pure  sea  water,  while  others  do  well 
in  brackish,  impure,  or  comparatively  fresh  waters.  Sometimes 
the  parts  of  timbers  that  are  near  the  surface  of  the  water  are 
injured,  and  sometimes  the  parts  that  are  down  near  the  bottom. 
These  and  other  differences  are  accounted  for  by  the  facts  that 
there  are  many  species  of  shipworms,  and  that  differences  some- 
times exist  between  the  qualities  of  higher  and  lower  layers  of 
water.  For  example,  when  fresh  water  from  a  river  meets  the 
heavier  water  of  the  sea,  shipworms  may  sometimes  be  found  near 
the  bottom  where  the  water  is  actually  salt. 

Some  shipworms  (Xylotrya  fimbriata)  survive  in  the  brackish,  polluted 
waters  of  New  York  Harbor,  while  other  species  that  do  not  exist  in 
these  waters  are  present  in  the  nearby  ocean.  Shipworms  are  very 
active  along  the  north  Pacific  Coast  but  are  said  to  be  absent  at  some 
points  near  the  mouth  of  the  Columbia  River  because  fresh  water  pre- 
dominates at  these  points.  A  vessel  carrying  hardwood  logs  was 
wrecked  in  the  vicinity  of  the  Gulf  of  Mexico.  The  logs  were  conveyed 
to  the  sheltered,  but  brackish,  waters  of  a  creek  where  they  remained 
for  about  six  weeks.  The  pieces  were  attacked  as  soon  as  they  were 
placed  in  the  creek  and  the  results  were  so  noticeable  that  some  borings 
were  measured  and  are  said  to  have  been  six  inches  in  length.  The 


MARINE  AND  TERRESTRIAL  WOODBORERS  307 

wood  that  remained  in  the  outer  ocean  was  not  injured.1  The  dis- 
crepancies between  these  incidents  may  be  accounted  for  by  the  presence 
of  different  species  of  ship  worms. 

The  belief  that  shipworms  are  influenced  by  impurities  in 
water  was  expressed  in  Holland  as  early  as  1733.  It  was  noticed 
that  comparatively  little  rain  fell  in  years  when  shipworms  were 
quite  plentiful,  and  it  was  thought  that  the  diminished  volumes 
of  river  water  during  these  years  permitted  larger  quantities  of 
salt  to  exist  in  the  waters  near  the  mouths  of  the  rivers.  Analyses 
proved  that  the  proportions  of  salt  did  vary  during  the  dry  and 
rainy  seasons. 

Method  of  Attack. — While  the  ship  worm  is  yet  very  small,  it 
settles  upon  the  surface  of  the  wood  and  almost  immediately 
begins  to  clear  away  a  place  through  which  to  burrow.  There 
is  some  controversy  as  to  the  method  by  which  the  burrow  is 
excavated,  but  it  is  quite  certain  that  the  foot  assists  the  shell. 
The  details  are  not  perfectly  understood,  but  the  facts  are  that 
the  hardest  woods  are  penetrated  and  that  surfaces  are  cut  as 
smoothly  as  though  a  sharp  chisel  had  been  employed. 

Character  of  Excavation. — A  shipworm  is  very  small  when  it 
enters  a  piece  of  wood,  but  once  within  develops  rapidly  and 
then  never  leaves  its  burrow.  The  perforation  through  which 
the  shipworm  enters  is  very  small,  but  the  diameter  of  the  boring 
increases  rapidly,  the  average  being  reached  at  a  point  quite 
near  the  perforation  through  which  the  shipworm  entered.  A 
shipworm  grows  principally  in  length  and  must  therefore  tunnel 
to  secure  space  for  the  increasing  length  of  its  body. 

The  shipworm  does  not  encroach  upon  other  tunnels  because 
most  of  these  tunnels  are  occupied  by  shipworms.  It  instinc- 
tively avoids  knots,  imperfections,  bark,  cracks,  and  lines  of 
cleavage.  Woods  are  not  exempt  from  attack  simply  because 
they  are  hard. 

Wood  may  appear  to  be  sound  and  yet  be  so  weak  that  it  can 
be  crushed  by  the  hand.  As  much  as  fifty  per  cent,  of  the  weight 
of  a  piece  may  be  removed  without  much  evidence  upon  the  out- 
side. Failures  often  come  suddenly  and  without  warning.  The 
tops  of  piles  thought  to  be  in  good  condition  are  seen  floating 
away.  A  freight  train  on  the  Louisville  and  Nashville  Railway 

1  Reported  to  the  writer  by  Messrs.  Nesmith  and  Constantine  of  New  York, 
1897. 


308 


ORGANIC  STRUCTURAL  MATERIALS 


crushed   through  a  trestle  that  had  been  standing  about  ten 
months  and  that  had  been  frequently  inspected. 

Size  of  Borings. — The  size  of  a  boring  depends  upon  that  of  the 
shipworm  that  made  it,  and  the  size  of  the  shipworm  depends 
upon  its  age  and  species.  Five  inches  and  as  many  feet  may  be 
regarded  as  minimum  and  maximum  lengths.  One-quarter  of 


FIG.  55. — End  of  log  of  Panama  mahogany  destroyed  in  one  season. 

an  inch  is  a  small  diameter  from  which  measurements  have  been 
made  up  to  one  and  one-eighth  inches.1  It  is  safer  to  disregard 
minimum  possibilities  in  such  a  connection. 

Rapidity  of  Work. — Evidence  upon  this  subject  is  seldom  ac- 
companied by  statements  of  conditions  under  which  the  results 
were  accomplished,  so  it  is  sometimes  hard  to  associate  the  boring 

1  Measured  by  the  writer  in  a  specimen  from  the  North  Pacific  Coast. 


PLATE   X.    WORK  OF  SHIPWORM— LARGE  BORINGS 


The  large  circle  near  the  top  of  the  picture  shows  a  boring  actually 
in.  in  diameter. 

(Facing  page  308.) 


L 


MARINE  AND  TERRESTRIAL  WOODBORERS     309 

with  the  species  that  made  it.  The  species  of  the  woodborer, 
the  location  of  the  piece,  the  season,  and  the  kind  of  wood  in 
which  the  boring  exists  are  all  important. 

Conditions  that  influence  the  growth  of  the  ship  worm  influence 
the  speed  with  which  it  works.  Generally  speaking,  cold  retards 
while  heat  expedites  the  work  of  excavation.  A  six-inch  burrow 
may  be  driven  in  as  many  weeks  so  that  a  one-foot  pile  attacked 
on  all  sides  can  be  destroyed  in  that  length  of  time.  On  the 
contrary,  other  pieces  remain  practically  intact  for  many  years. 

Wood  has  been  found  to  contain  shipworms  after  a  submergence  of 
eight  days  (United  States  Annual  Report  of  Scientific  Discovery  of 
1857).  Six-inch  piles  were  destroyed  at  Aransas  Pass  in  six  weeks; 
other  piles  in  the  same  locality  have  lasted  as  long  as  three  or  four 
months  (Report,  Chief  of  Engineers,  U.  S.  A.,  1888,  pp.  13,  14).  Piles 
have  been  destroyed  in  one  hundred  days  in  Mobile  Bay  (Annual  Report, 
Chief  of  Engineers,  U.  S.  A.,  1879,  p.  937) .  Piles  on  the  line  of  the  Louis- 
ville and  Nashville  Railroad  sometimes  have  to  be  replaced  after  six 
months  service  (Transactions,  Am.  Soc.  C.  E.,  Vol.  XXXI,  p.  221, 
Montfort).  Unpainted  spar  buoys  have  a  life  of  about  one  year  in  the 
vicinity  of  Cape  Cod  (Report  to  United  States  Fish  Commission  by 
Captain  Edwards).  Piles  have  been  destroyed  in  the  harbor  of  Galves- 
ton  in  three  years  (Report,  Chief  of  Engineers,  U.  S.  A.,  1868,  p.  512). 
Piles  have  lasted  as  long  as  twelve  years  in  the  harbor  formed  by  the 
Delaware  Breakwater  (Annual  Report,  Chief  of  Engineers,  U.  S.  A., 
1871,  p.  667). 

Field  of  Attack. — The  fact  that  a  shipworm  lives  upon  micro- 
scopic life  present  in  sea  water  outside  its  burrow,  makes  it 
necessary  for  its  siphon  extremities  to  be  located  at  the  entrance 
to  its  burrow.  This  end  of  the  shipworm  being  fixed  as  to  posi- 
tion, the  wood  is  removed  inward  from  the  surface  to  a  distance 
measured  by  the  increasing  length  of  the  shipworm. 

The  small  portals  to  the  burrows  that  are  evident  upon  the 
outside  of  the  timber  (see  Plate  IX)  do  not  necessarily  mark  the 
exact  content  of  wood  that  is  destroyed  within;  since,  although 
one  end  of  the  shipworm  must  remain  at  the  entrance  to  its 
burrow,  the  other  can  reach  upward  into  the  wood  above  the 
water,  or  downward  into  that  below  the  mud.  Shipworms  have 
been  known  to  work  under  pressures  caused  by  twenty  or  twenty- 
five  feet  of  water. 

Woods  Subject  to  Attack. — Immunity  is  sometimes  claimed 
for  some  particular  wood;  but  it  is  usually  found  that  such  a 


310  ORGANIC  STRUCTURAL  MATERIALS 

claim,  based  upon  local  conditions,  is  not  generally  substantiated. 
It  is  safer  to  assume  that  all  ordinary  woods  may  be  attacked  by 
these  forms.  Doubt  may  be  felt  with  regard  to  some  woods  that 
contain  repellent  gums,  resins,  or  bitter  essences,  and  some  palms 
that  have  open,  porous  structure;  yet  very  few  woods  such  as 
these  are  used  in  American  constructions. 

Woods  are  not  safe  simply  because  they  are  hard.  Osage 
Orange,  which  is  a  very  hard  wood,  has  failed  in  several  instances 
where  it  has  been  used  for  piles.  A  Commission  appointed  in 
Holland  to  investigate  this  question  reported  as  follows: 

"Although  we  do  not  know  with  any  certainty  whether  among  exotic 
woods  there  may  not  be  found  those  which  resist  the  shipworm,  we  can 
affirm  that  hardness  is  not  an  obstacle  that  prevents  the  mollusk  from 
perforating  its  galleries." 

THE  LIMNORIA  (Limnoria  lignorum). — -This  isopod  crusta- 
cean, which  has  other  names  as 
the  wood  flea,  sand  flea,  gribble, 
and  boring  gribble,  is  the  prin- 
cipal one  of  several  similar 
forms  that  attack  woods  when 
in  sea-water.  The  Limnoria  is 
much  smaller  than  the  shipworm, 
FIG.  56.— The  Limnoria.  but  it  usually  occurs  in  larger 

numbers  and  in  some  localities 
is  almost  equally  destructive. 

The  Limnoria  is  found  along  the  Atlantic  Coast  from  Nova 
Scotia  to  Florida.  It  exists  sparingly  in  Long  Island  Sound;  but 
is  abundant  along  the  Coast  of  Massachusetts,  and  very  destruc- 
tive in  the  Bay  of  Fundy.  It  is  also  active  in  the  north  Pacific,  as 
in  Puget  Sound  and  the  Straits  of  San  Juan  de  Fuca.  It  is  said 
to  exist  upon  the  coast  of  Great  Britain  and  in  other  European 
waters. 

Form  and  Physiology. — The  Limnoria  is  about  as  large  as  a 
grain  of  rice.  The  nearly  straight  sides  are,  in  a  general  way, 
parallel  to  one  another,  while  the  ends  are  rounded.  The  upper 
and  lower  surfaces  are  flattened,  the  former  being  covered  with 
small  hairs  to  which  more  or  less  dirt  often  adheres.  The  body 
is  made  up  of  fourteen  segments.  To  each  of  the  seven  segments 
that  follow  the  head  is  attached  a  pair  of  short,  stout  legs  ter- 
minating in  claws,  the  shape  of  which  suggests  the  small  claws  of 
the  lobster. 


MARINE  AND  TERRESTRIAL  WOODBORERS  311 

The  body  of  the  Limnoria  is  grayish  in  color,  and  sometimes 
resembles  the  color  of  the  wet  wood  so  much  that  it  is  difficult 
to  distinguish  it.  The  Limnoria  can  swim,  creep  "backward  and 
forward,  as  well  as  jump  backward  by  means  of  its  tail.  When 
touched,  it  rolls  itself  into  a  ball,  and  in  this  particular,  as  well  as 
in  general  appearance,  it  resembles  the  common  sow-bug. 

The  Limnoria  differs  from  the  ship  worm  in  that  quite  certainly  iib 
is  a  vegetarian.  The  shipworm  is  sustained,  at  least  for  the  most 
part,  by  microscopic  life  drawn  from  the  sea  water,  but  the  Lim- 
noria devours  wood.  Its  tunnel  affords  both  food  and  shelter. 

Influence  of  Temperature  and  Water. — Limnoria  are  plentiful 
in  some  regions  in  the  North  where  shipworms  can  exist  but  spar- 
ingly because  of  the  cold.  Limnoria  require  pure  sea  water  and 
are  seldom  found  in  the  comparatively  fresh  waters  encountered 
near  the  mouths  of  rivers. 

Method  of  Attack. — Character  of  Excavation. — The  Limnoria 
attacks  the  wood  by  means  of  its  mandibles  or  jaws.  It  prefers 
wet  wood  and  succeeds  in  making  a  very  clean-cut  excavation. 

The  work  of  the  Limnoria  differs  from  that  of  a  shipworm  in 
that  its  tunnels  terminate  on  the  surface  of  the  wood  where  they 
can  be  plainly  seen,  whereas  those  of  the  shipworm  are  for  the 
most  part  concealed  within  the  wood.  The  body  of  the  shipworm 
cannot  emerge  from  the  wood  within  which  it  has  located,  while 
that  of  the  Limnoria  can  pass  freely  in  and  out.  The  Limnoria 
frequently  works  in  conjunction  with  the  shipworm.  It  attacks 
the  surface,  while  the  shipworm  takes  away  from  the  interior  of 
the  woodwork. 

The  numberless,  smooth,  clean-cut  galleries  are  close  together 
and  the  partitions  that  separate  them  are  so  thin  that  they  can- 
not long  resist  the  action  of  the  waves.  Later,  the  partitions  are 
either  washed  away  by  the  waves,  or  they  decay.  Fresh  sur- 
faces are  then  exposed  and  these  are  destroyed  in  the  same  man- 
ner. Layer  after  layer  is  removed  until  the  timber  is  destroyed. 
The  Limnoria  can  penetrate  knots,  but  sometimes  avoids  them, 
when  such  hard  portions  stand  out  in  relief  as  the  other  parts  are 
destroyed. 

Size  of  Borings. — The  Limnoria  is  very  small,  but  notwith- 
standing this  fact,  it  is  very  destructive.  The  multitude  of  these 
woodborers  compensates  for  their  size.  Each  may  be  assumed 
to  be  from  one-sixth  to  one-fourth  inch  in  length  and  about 
one-sixteenth  of  an  inch  in  diameter.  The  tunnels  are  about 


312 


ORGANIC  STRUCTURAL  MATERIALS 


one-half  of  an  inch  in  length  and  about  one-tenth  of  an  inch  in 
diameter. 

Rapidity  of  Work. — The  Limnoria  does  not  work  as  rapidly  as 
the  shipworm.     The  number  of  individual  workers  must  in  this 


FIG-  57. — Knot  showing  surface  from  which  work  of  Limnoria  has  been 
removed  by  waves.     (Reduced.) 

case  be  taken  as  a  measure  of  the  rapidity  of  destruction.  The 
number  of  tunnels  is  more  important  than  their  depth.  The 
thickness  of  a  piece  of  timber  may  be  reduced  from  one-fourth  of 
an  inch  to  as  much  as  an  inch  in  a  year.  Much  wood  used  in 
marine  constructions  is  in  the  form  of  piles  that  are  necessarily 
exposed  on  all  sides.  The  effective  diameters  of  such  pieces  are, 


PLATE  XI.     WORK  OF  THE  LIMNORIA 


MARINE  AND  TERRESTRIAL  WOODBORERS  313 

therefore,  reduced  twice  as  rapidly  as  indicated  by  the  figures 
noted. 

Field  of  Attack. — The  depredations  of  Limnoria  are  confined  to 
a  limited  distance  above  and  below  the  low-water  mark.  Where 
the  variations  of  the  tides  are  extensive,  as  in  the  vicinity  of  the 
Bay  of  Fundy,  the  range  of  the  Limnoria  is  correspondingly  great. 
It  has  been  found,  although  rarely,  at  a  depth  of  forty  feet. 

Woods  Subject  to  Attack. — Most  woods  used  by  American  con- 
structors in  waters  where  these  forms  are  prevalent  are  subject  to 
attack  by  them. 

THE  CHELURA  (Chelura  terebrans). — It  is  of  ten  stated  that  the 
Chelura  is  among  the  active  enemies  of  woods;  but  efforts  made 
to  discover  work  actually  per- 
formed by  it  have  proved  un- 
fruitful, and  it  is  not  known 
where  this  form  exists  as  a 
specimen  and  where  it  exists 
as  a  real  pest.  It  is  probable  FlQ.  53.— The  Chelura. 

that  some  results  attributed 

to  the  Chelura  were  actually  caused  by  the  Limnoria.  The 
Chelura  is  also  known  as  the  wood  shrimp. 

Form  and  Physiology. — The  Chelura  is  an  amphipod  crusta- 
cean. The  form  differs  strikingly  from  that  of  the  Limnoria, 
except  in  size,  and  resembles  that  of  the  ordinary  shrimp.  The 
body  is  semi-translucent  and  spotted  or  mottled  with  pink. 
There  are  three  pairs  of  caudal  stylets,  the  last  of  which  is  nearly 
as  long  as  the  body.  The  Chelura  swims  actively  upon  its  back, 
and,  like  the  sand-hopper,  can  project  itself  to  a  considerable 
distance  when  placed  upon  dry  land.  The  Chelura  resembles 
the  Limnoria  in  that  it  also  is  a  vegetarian.  Its  burrow  affords 
both  residence  and  food. 

Method  of  Attack.  Character  of  Excavation.— The  work  of 
the  Chelura  and  that  of  the  Limnoria  resemble  one  another  in  so 
many  particulars  that  the  suspicion  is  warranted  that  the  two 
forms  have  been  confused  with  one  another.  In  both  cases,  the 
wood  is  attacked  from  without,  and  numerous  tunnels  are  driven 
until  the  weakened  layer  succumbs  to  the  action  of  the  waves.  A 
new  surface  is  exposed  and  this  is  eventually  destroyed  in  the 
same  manner.  The  few  specimens  observed  do  not  warrant  wide 
generalizations,  but  it  is  possible  that  the  Chelura  prefers  the 
ofter  portion  of  the  annual  layer,  and  that  the  tunnels  are 


314  ORGANIC  STRUCTURAL  MATERIALS 

curved,  because  these  points  were  noticed  in  the  few  specimens 
available. 

Size  of  Borings.  —  The  Chelura  is  somewhat  larger  than  the 
Limnoria.  The  specimens  seen  were  about  one-third  of  an 
inch  in  length.  The  burrows  were  a  little  larger  than  those  of  the 
Limnoria. 

Field  of  Attack.  —  The  specimens  observed  were  found  at  Prov- 
incetown,  in  wood  located  about  ten  feet  below  the  low-water  level. 
MISCELLANEOUS.  Fresh-water  Woodborers.—  The  work 
of  a  fresh-water  woodborer  (Sphceroma  destructor  Richardson) 
in  trestles  of  the  Florida  East  Coast  Railway  resembles  the  work 
of  the  Limnoria,  save  that  the  burrows  of  the  fresh-water  borer 
are  larger  than  those  of  the  Limnoria.  A  yellow  pine  pile  was 
reduced  by  them  from  a  diameter  of  sixteen  inches  to  one  of  seven 
and  one-half  inches  in  eight  years.1  Several  kinds  of  fresh- 
water woodborers,  some  of  them  very  large,  have  been  found  in 
Australian  rivers.2 

Barnacles  (Lepas  antifera).  —  Barnacles  do  not  injure  wood. 
On  the  contrary,  they  protect  such  parts  as  are 
covered  by  them  from  the  attacks  of  marine 
woodborers.  Barnacles  attach  themselves,  singly 
or  in  clusters,  to  floating  or  submerged  wood-work 
and  are  disliked  by  ship  owners  because  bottoms 
covered  in  such  a  manner  cannot  move  as  rapidly 
through  the  water. 

Stone-borers.  —  Stone-borers  are  interesting  be- 
cause they  show  the  power  of  forms  that  are 
apparently  feeble.  The  pholas  or  piddock  (Pholas 
dactylus)  is  a  typical  species  of  the  molluscan 
family  Pholadidse,  which  includes  other  stone- 
borers  as  well.  The  pholas  bores  in  stone  by 
59  so  as  to  "  tne 


Barnacle(Le- 

pas  antifera  re-  excavation.     The   long    foot   or   pestle,  similar  to 


"  that  of  the  teredo>  is  then  thrust  out  and  rubbed 
against  the  stone.      The   process  is    assisted    by 
particles  of  sand  or  rock.3 

1  See  report  by   Harriet   Richardson    (Biological  Society,   Washington, 
May  13,  1897). 

2  Correspondence  Professor  Charles  Hedley,  Sydney,  Australia. 

3A  cargo  of  marble  wrecked  in  the  North  Atlantic  was  destroyed  in  one 
year  by  a  boring  sponge  (Cliona  sulfurea  Vcrrill).  The  shells  of  live 
oysters  are  often  attacked. 


PLATE  XII.     WORK  OF  THE  CHELURA 


V 


bJO 


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o 

-fj 

bfi 

fl 

1 

a 


I 

o 

— 

I 

£ 

| 

-M 
o 

£ 


MARINE  AND  TERRESTRIAL  WOODBORERS     315 


FIG.  60. — Stoneborer  in  sandstone.     (Life  size.) 

PROTECTION  FROM  MARINE  WOODBORERS 

Many  of  the  attempts  made  to  protect  woods  from  the  attacks  of 
marine  woodborers  have  failed,  but  some  have  succeeded.  The 
methods  usually  considered  are  as  follows: 

Removal  During  the  Breeding  Season. — This  method,  which 
may  be  used  to  protect  such  objects  as  buoys,  bathing  houses, 
and  rowboats,  is  applicable  only  where  the  breeding  season  is 
short,  as  in  the  North. 

Change  of  Water. — Wooden  vessels  attacked  by  sea  wood- 
borers  are  sometimes  hauled  into  fresh  or  muddy  waters.  In 
the  past  several  attempts  have  been  made  to  protect  special 
woodwork  by  surrounding  it  with  fresh  water. 

Use  of  Selected  Woods. — The  few  woods  for  which  claims  have 
been  made  are  not  generally  employed  in  construction,  and  it  is 
not  urged  that  any  one  of  these  woods  is  always  exempt.  Thus 
far  evidence  favors  palm  and  palmetto,  probably  because  these 
woods  have  loose,  open  structures. 

External  Coatings. — This  form  of  treatment  is  good  because 
applications  can  be  limited  to  the  parts  of  timbers  exposed  to 
attack.  The  parts  much  above  the  high-water  mark  and  those 
much  below  the  mud  line  do  not  have  to  be  protected.  External 
coatings  are  defective  in  that  they  ultimately  succumb  to  blows 
from  waves,  ships,  and  other  floating  objects. 

(a)  The  bark  sometimes  left  upon  logs  protects  them  as  long 
as  the  bark  remains  intact.  This  is  explained  by  the  reluctance  of 
shipworms  to  cross  seams.  The  bark  is  soon  loosened  and  re- 
moved by  the  waves, 


316  ORGANIC  STRUCTURAL  MA TE RIALS 

(6)  Planks  joined  closely  over  the  surface  of  woodwork  will 
protect  it  from  ship  worms  as  long  as  the  planks  remain. 

(c)  Copper  and  other  metals  have  been  used  to  enclose  piles 
as  well  as  the  bottoms  of  wooden  vessels.     These  coatings  are 
expensive  but  do  protect  against  all  forms  of  marine  woodborers 
as  long  as  they  remain  intact. 

(d)  Teredo-nails  or  worm-nails,  said  to  have  originated  with 
the  Romans,  resemble  ordinary  carpet,  upholstery,  anc(  thumb 
tacks,  in  that  they  have  short  spikes  and  large,  flat  heads.     These 
nails  are  driven  close  together  until  the  wood  is  enclosed  by  the 
heads.     Experiments  with  teredo-nails  have  been  made  by  the 
New  York  Department  of  Docks.1 

(e)  Paraffin,  tar,  asphalt,  paints,  and  other  mixtures  have  been 
used  to  protect  woods  from  marine  woodborers,  but  usually  do 
not  remain  long  in  place,  since  the  coatings  that  are  not  softened 
by  the  water  are  likely  to  be  removed  by  erosion.     This  form  of 
protection  should  be  frequently  inspected. 

(/)  Coatings  are  sometimes  reinforced  by  wire  net  or  by  burlap. 
A  paraffin  mixture  reinforced  by  burlap  has  been  used  to  protect 
piles  by  the  California  State  Board  of  Harbor  Commissioners, 
the  Northern  Pacific  Railway,  and  the  Great  Northern  Railway. 

The  bark  was  removed  and  the  surface  of  the  pile  covered  with  a  mix- 
ture of  powdered  limestone,  clay,  and  paraffin.  It  was  then  wrapped 
in  burlap;  another  coat  of  the  compound  was  applied  and  wooden  battens 
were  nailed  up  and  down  to  keep  the  coatings  in  place.2 

(g)  Portland-cement  mortar  has  been  applied  to  piles  after 
they  had  been  driven.  This  is  a  good  method  in  that  the  cement 
can  be  limited  to  the  parts  that  are  in  danger;  but  it  has  not 
proved  adequate  because  the  cement  being  comparatively  brittle 
is  in  danger  of  being  cracked  and  destroyed.  The  cement  is 
applied  in  several  ways.  Piles  are  sometimes  encircled  by  sewer 
pipes,  the  spaces  between  the  pipes  and  piles  being  filled  with 
cement.  Sometimes  iron  moulds,  which  are  removed  as  soon  as 
the  cement  is  set,  are  employed.3 

1  See  "Transactions  American  Society  of  Civil  Engineers"  (Vol.  XXXI, 
p.  235).     The  " Dutch  Waterstaat"  specifies  that  nails  must  be  well  forged 
and  not  brittle.     Diameters  must  be  3  cm.  and  lengths  must  be  4  cm.     One 
kilogram  must  contain  from  thirty  to  thirty-four  nails. 

2  "Engineering  News,"  February  8,  1894. 

3  The  Louisville  and  Nashville  Railroad  treated  four  thousand  piles  in  this 
way,  at  an  average  cost  of  $1.25  per  foot  of  length  (Transactions  American 
Society  of  Civil  Engineers,  Vol.  XXXI,  p.  225), 


MARINE  AND  TERRESTRIAL  WOODBORERS 


317 


(h)  Piles  are  also  enclosed  by  sand.  Sewer  pipes  are  used  and 
the  spaces  between  pipes  and  piles  are  filled  with  sand  instead  of 
cement.  The  cost  is  less  than  for  cement,  while  imperfections, 
serious  enough  to  permit  the  sand  to  escape,  are  revealed  by  the 
settlement  of  the  sand  at  the  top.  Piles  treated  in  this  manner 
are  said  to  have  been  sound  after  twenty  years  of  service.1 


FIG.  61. — Piles  protected  by  pipes  and  sand. 2 

(i)  Protection  is  sometimes  afforded  naturally  by  oysters, 
barnacles,  and  other  forms. 

Preservatives  Applied  Within  Woods. — Of  the  many  mixtures 
that  have  been  used  to  repel  the  attacks  of  marine  woodborers, 
creosote  alone  deserves  attention.  Experience  has  shown  that 
sufficient  quantities  of  good  coal-tar  creosote,  well  applied  to 

1  Transactions  American  Society  Civil  Engineers,  Vol.  XXXI,  p.  221. 

2  Photograph  by  Lockjoint  Pipe  Company. 


318  ORGANIC  STRUCTURAL  MATERIALS 

appropriate  woods,  will  protect  the  woods  from  marine  wood- 
borers  during  terms  that  may  be  measured  by  the  durability  of 
the  creosote.     Creosoted  piles  have  stood  against  the  attacks  of         /, 
shipworms  for  as  long  as  forty  years.     The  failures  that  have 
taken  place  were,  in  almost  every  case,  due  to  poor  or  insufficient      ,  T 
creosote,  or  to  poor  methods  of  application.  V  ~J\&&+^£t  \yLk~Jubve 
Substitution. — Substitution   is   not    protection,    but,    in   this       / 
connection,  it  is  well  to  remember  that  other  materials  can  often 
be  used  in  place  of  wood.     If  iron  had  not  so  largely  replaced 
wood  in  marine  constructions,  sea  woodborers  would  require 
more  attention  than  they  now  receive. 

TERRESTRIAL  WOODBORERS 

The  total  losses  caused  by  terrestrial  woodborers  are  enor- 
mous. Many  trees  are  completely  destroyed  by  them.  But, 
as  distinct  from  trees,  woods  in  construction  do  not  suffer  unduly 
from  these  pests.  The  losses  in  this  direction  are  less  than  from 
fire  or  from  rot. 

If  plant  products,  growing  and  in  storage,  be  included  with  live  stock, 
the  losses  due  to  depredations  of  insects  in  general  would  compare  with 
the  yearly  expenditures  of  the  National  Government.  It  has  been  esti- 
mated that  the  total  injury  to  agricultural  products  in  the  United  States 
by  insects  amounts  to  $700,000,000.  annually.1 

Terrestrial  woodborers  are  too  numerous  for  any  save  the  most 
general  notice.  Most  of  them  are  insects,  and  it  is,  therefore,  well 
to  remember  that  all  insects  are  grouped  according  to  the  way  in 
which  they  develop  from  the  egg  to  the  adult.  First,  some 
insects  develop  with  what  is  known  as  complete  metamorphosis; 
second,  others  develop  with  incomplete  metamorphosis;  and 
third,  still  others  develop  without  any  metamorphosis. 

In  the  first  case  the  egg  liberates  the  larva,  sometimes  popularly 
known  as  "worm,"  which  changes  to  the  pupa,  which  in  turn 
changes  to  the  adult  or  imago.  The  Colorado  potato  beetle  is  an 
example.  The  egg,  the  thick  larva,  the  pupa,  and  the  adult 
beetle  may  often  be  observed  upon  a  single  potato  plant.  In  the 
second  case  the  egg  liberates  a  form  that  closely  resembles 
the  adult,  and  this  form,  known  as  the  nymph,  changes  directly 

1  Marlatt  (United  States  Department  of  Agriculture  Year  Book,  1904, 
p.  461);  also  "Insect  Injuries  of  Forest  Products,"  Hopkins  (United  States 
Department  of  Agriculture  Year  Book,  1904,  p.  381) ;  "  Guide  to  the  Study  of 
Insects,"  Packard. 


PLATE  XIII.     WORK  OF  LARV.E  OF  BEETLES— "  BOOK  WORMS" 


Corner  of  Book  Cover,  Tarry  town,  New  York.     Perforations  Reduced 

One-half. 


Whitewood  Bureau  Drawer-Bottom,  New  York  City.     Life  Size. 


Yellow  Pine  Base-Board,  New  York  City.     Life  Size. 

(Facing  page  318.) 


MARINE  AND  TERRESTRIAL  WOODBORERS  319 

to  the  adult.  The  locust  is  one  of  the  forms  that  develop  with 
incomplete  metamorphosis;  the  nymph  of  the  locust  is  like  the 
adult,  save  that  it  has  no  wings.  In  the  third  case,  the  egg 
liberates  a  form  that  resembles  the  adult  in  practically  all  re- 
spects save  size.  Development  without  metamorphosis  takes 
place  in  but  a  single  order  of  insects  (Thysanura).  The  bristle- 
tails  are  examples. 

Some  insect  woodborers  attack  the  bark  or  wood  of  living  trees 
while  others  are  associated  with  woods  that  are  ready  for,  or 
already  in,  construction.  Some  prefer  sound  and  healthy  woods, 
and  others  prefer  those  that  are  moist  and  decayed.  Some  insects 
are  particularly  associated  with  certain  species  of  trees,  and 
among  these  are  groups  known  as  hickory  borers,  elm  borers,  and 
the  like.  There  are  several  hundred  insect  enemies  of  oak  alone. 
BEETLES  (Order  Coleoptera). — Beetles  form  what  is  known  to 
naturalists  as  an  Order.1  This  one  includes 
almost  one  hundred  thousand  species;  besides 
which,  others  are  frequently  discovered. 
Beetles  undergo  a  complete  metamorphosis. 
The  larvae  are  sometimes  called  grubs. 
Beetles  have  two  horny  sheaths  or  wing- 
covers  that  meet  in  a  straight  line  down 
the  back  over  a  single  pair  of  wings.  Their 
mouths  are  formed  for  biting,  and  are  some- 
times so  powerful  as  to  be  able  to  make  an 
impression  upon  soft  metal.  Most  wood- 
boring  beetles  attack  live  trees,  but  some  at- 
tack woods  in  construction.  Most  of  those  tion^in  sheet-lead 
that  attack  woods  do  so  while  they  are  in  the  roof  made  by  adult 
larval  condition,  but  some  are  harmful  after 
they  have  become  adults.  It  is  common  to  refer  to  all 
woods  that  have  been  injured  by  beetles  and  other  insects  as 
"  worm-eaten  woods,"  even  although  the  adult,  as  distinct  from 
the  larva,  was  responsible  for  the  borings  noticed. 

The  family  Scolytidse  includes  many  forms  that  attack  trees. 
Some  bore  in  twigs  and  are  known  as  "twig  beetles,"  others  bore 
in  roots  and  are  known  as  "root  beetles,"  and  still  others  attack 
bark  and  are  known  as  "bark  beetles."  Some  members  of  this 
family  cut  symmetrical  grooves  upon  the  outer  surfaces  of  the 

1  The  animal  kingdom  is  divided  into  Phyla,  Classes,  Orders,  Families, 
Genera,  Species,  and  Individuals,  the  importance  being  in  the  order  named. 


320  ORGANIC  STRUCTURAL  MATERIALS 

sapwood  of  trees  and  are  known  as  "engraver  beetles."  The 
powder-post  beetles  include  many  enemies  of  seasoned  woods  that 
attack  house-trim,  flooring,  spokes,  tool  handles,  and  the  like. 

The  larvae  of  some  beetles  attack  the  paste,  covers,  and  leaves  of 
books  as  well  as  woodwork,  and  are  often  known  as  "book- 
worms." The  worm-eaten  appearance  of  furniture  is  often  due 
to  them.  An  instance  is  on  record  of  a  bedpost  destroyed  thus  in 
three  years.  The  name  bookworm  is  not  confined  to  any  par- 
ticular species  but  applies  to  any  form  of  insect  life  that  attacks 
the  covers,  leaves,  or  paste  of  books.1 

Summary. — Although  very  numerous,  beetles  are  principally 
harmful  to  living  trees,  and  for  this  reason  protective  measures  are 
almost  wholly  in  the  hands  of  growers,  foresters,  and  horticul- 
turists. The  total  amount  of  wood  in  construction  that  is  injured 
by  beetles  is  comparatively  small.  Engineers  seldom  attempt 
to  protect  woods  from  the  attacks  of  beetles.2 

MOTHS  AND  BUTTERFLIES  (Order  Lepidoptera) .—Moths 
and  butterflies  undergo  complete  metamorphosis.  Both  forms 
possess  four  membranous,  scaly  wings,  and  in  both  cases  the 
larva  are  often  known  as  caterpillars.  Butterflies  fly  by  day, 
while  moths  fly  by  night,  and  there  are  also  differences  in  the  ways 
in  which  the  wings  are  folded.  Adult  moths  and  butterflies  do 
not  attack  trees  or  woods  in  construction,  but  the  larvae  of  some 
species  of  both  are  very  destructive.  With  few  exceptions,  liv- 
ing trees,  as  distinct  from  woods  in  construction,  suffer  from  their 
attacks. 

The  Gypsy  Moth  (Porthetriadispar).3 — The  destruction  accom- 
plished by  the  larvae  of  this  species,  by  their  habit  of  feeding  on 

1  The  silver  fish  (Lepisima  saccharina]  often  attacks  paper. 

2  "  Insects  Injurious  to  Forest  Products,"  Hopkins  (United  States  Depart- 
ment of  Agriculture  Year  Book,  1904,  pp.  387-388);  "A  Revision  of  the 
Powder-Post  Beetles  of  the  Family  Lyctidae,"  Kraus  and  Hopkins  (United 
States  Bureau  of  Entomology,  Technical  Series  No.  20,   Part   3,    1911); 
"Principal  Household  Insects,"  Howard  and  Marlatt  (United  States  Divi- 
sion of  Entomology,  Bulletin  No.  4,  pp.  76-78);  etc.,  etc. 

3  See  also  "The  Gypsy  Moth,"  Forbush  and  Fernald  (Massachusetts  State 
Board  of  Agriculture,  1896);  "Report  on  the  Field  Work  against  the  Gypsy 
Moth  and  the  Brown-Tail    Moth,"   Rogers  and  Burgess  (United  States 
Bureau  of  Entomology,  Bulletin  No.  87,  1910);  "Insects  Affecting  Park  and 
Woodland  Trees"  (New  York  State  Museum,  Vol.  I,  pp.  79-84);  "The 
Importation  into  the  United  States  of  the  Parasites  of  the  Gypsy  Moth  and 
Brown-Tail  Moth,"  Howard  and  Fiske  (United  States  Bureau  of  Ento- 
mology, Bulletin  No.  91,  1911);  etc.,  etc. 


MARINE  AND  TERRESTRIAL  WOODBORERS 


321 


leaves,  has  been  so  great  that,  in  Europe,  it  has  been  referred  to  as 
"the  plague,"  and, in  the  past,  it  has  been  thought  to  be  a  scourge 
sent  by  the  Almighty  as  a  penalty  for  wrong-doing.  The  Gypsy 
Moth  was  brought  to  the  United  States  in  1868,  but  remained 
unrecognized  until  1889.  The  work  of  the  National  Government 
and  of  the  different  States  in  combating  this  pest  has  produced 
encouraging  results. 

The  Goat  Moth  (Cossus  ligmperda). — The  young,  which  are 
said  to  remain  in  a  larval  condition  for  as  long  as  three  years, 
possess  wedge-shaped  heads  with  large,  trenchant  jaws,  equipped 
with  powerful  muscles  that  enable  them  to  cut  into  very  hard 
woods.  The  Carpenter  Worm  is  the  larva  of  a  beautiful  gray 
moth  (Prionoxystus  robinice)  with  wings 
that  spread  over  a  distance  of  about 
three  inches.  The  full  grown  larva,  which 
is  about  two  and  one-half  inches  long, 
sometimes  bores  into  trunks  of  oaks,  ma- 
ples, and  locusts  to  such  an  extent  that 
such  woods  have  very  little  value  later. 

Summary. — The  larvae  of  moths  and 
butterflies  are  among  the  most  dreaded 
insect  enemies  of  living  trees.  Woods  in 
construction  are  seldom  injured.  Pro- 
tective measures  are  in  the  hands  of  for- 
esters and  horticulturists.1 

TERMITES  (Order  Isoptera)  .—Ter- 
mites are  called  " white  ants"  because 
they  are  of  a  dingy,  white  color,  and  be- 
cause they  live  in  communities  as  true 
ants  do.  Termites  have  thick  waists  and 

develop    with  incomplete  metamorphosis,    ™ite(Termesbellicosus). 

.  *  '     (Natural  size.) 

whereas  true  ants  have  slender  waists  and 

develop  with  complete  metamorphosis.  The  mouths  of  ter- 
mites are  formed  for  biting.  The  American  termite  (Termes 

1  See  also  "The  Gypsy  Moth,"  Forbush  and  Fernald  (Massachusetts  State 
Board  of  Agriculture,  1896);  "Report  on  the  Field  Work  against  the  Gypsy 
Moth  and  the  Brown-Tail  Moth,"  Rogers  and  Burgess  (United  States 
Bureau  of  Entomology,  Bulletin  No.  87,  1910);  "Insects  Affecting  Park  and 
Woodland  Trees"  (New  York  State  Museum,  Vol.  1,  pp.  79-84);  "The 
Importation  into  the  United  States  of  the  Parasites  of  the  Gypsy  Moth 
and  Brown-Tail  Moth,"  Howard  and  Fiske  (United  States  Bureau  of  Ento- 
mology, Bulletin  No.  91,  1911);  etc.,  etc. 


FIG.  63.— Queen  ter- 


322  ORGANIC  STRUCTURAL  MATERIALS 

flavipes),  the    European    termite    (Termes    lucifugus),  and  the 
African  termite  (Termes  bellicosus)  are  important  species. 

Termites  are  encountered  in  the  Northern  States  in  hot-house 
plants,  dead  stumps,  and  under  stones.  They  have  destroyed 
live  trees  as  far  north  as  in  the  vicinity  of  Boston,  but  are  more 
plentiful  in  the  Southern  States,  and  are  very  destructive  in  the 
tropics,  where  they  occupy  a  position  among  land  woodborers 
that  compares  with  that  held  by  shipworms  among  marine  wood- 
borers.  Although  termites  sometimes  attack  live  plants  they 
seem  to  prefer  tissues  within  which  life  processes  have  ceased, 
and  house  timbers,  railway  ties,  and  other  structural  pieces,  as 
well  as  dead  stumps,  books,  and  papers,  are  subject  to  attack  by 
them. 

A  floor  in  the  National  Museum  at  Washington  was  undermined  sev- 
eral times  by  a  colony  of  termites  that  could  not  be  located,  until  it 
became  necessary  to  replace  the  floor  by  one  of  cement.  Termites  have 
destroyed  frame  buildings  in  Washington  and  Baltimore.  A  school 
library  in  North  Carolina  was  destroyed  during  the  summer  vacation. 
Humboldt  explains  the  rarity  of  old  books  in  Spain  by  the  fact  that 
termites  are  so  active  in  that  country. 

It  is  seldom  urged  that  any  wood  is  always  exempt  from  the 
attacks  of  termites;  but  some,  such  as  teak  and  redwood,  seem  to 
be  more  fortunate  than  others  in  this  respect.  Railway  ties  are 
not  often  attacked  by  termites,  not  because  of  the  kinds  of  wood 
that  are  used  but  because  of  the  disturbance  caused  by  passing 
trains.  Redwood  stave  pipes  have  resisted  termites  and  other 
insects  in  the  United  States  as  long  as  the  pipes  remained  wet. 

Some  methods  employed  to  protect  woods  from  termites  are  as 
follows:  (a)  Decayed  wood  that  is  likely  to  attract  or  shelter 
colonies  of  termites,  should  be  removed.  (6)  When  discovered, 
colonies  of  termites  should  be  destroyed  by  the  liberal  use  of 
steam,  hot  water,  kerosene,  or  other  agencies,  (c)  Saturation 
with  good  coal-tar  creosote  has  preserved  timbers  from  attack. 

REFERENCES. — "Dangers  from  White  Ants,"  Hagen  (American  Natural- 
ist, July,  1876,  pp.  401-410);  "Manual,"  Comstock  (pp.  95-97);  "Insects 
Injurious  to  Forest  Products,"  Hopkins  (United  States  Department  of 
Agriculture,  Year  Book,  1904,  p.  389);  "Important  Philippine  Woods," 
Ahern  (p.  91);  "Principal  Household  Insects,"  Howard  and  Marlatt  (United 
States  Division  of  Entomology,  Bulletin  No.  4,  pp.  70-76);  "The  White 
Ant,"  Marlatt  (United  States  Division  of  Entomology,  Circular  No.  50, 
Second  Series). 


PLATE  XIV.     WORK  OF  LARGE  CARPENTER  ANT 


•* '  *  -  •'•• 


(a)  Pine  Shingle  from  House  on  Long  Island. 


(6)  Fence  Post  from  New  York  City. 


(Facing  page  322.) 


MARINE  AND  TERRESTRIAL  WOODBORERS 


323 


(d)  As  far  as  possible  endangered  structures  should  be  surrounded 
by  cleared  spaces,  and  these  should  be  covered  with  asphalt  or 
gravel,  (e)  In  the  tropics,  tables  and  other  kinds  of  furniture  are 
sometimes  protected  by  placing  the  legs  in  small  vessels  contain- 
ing oil.  (/)  Books  and  papers  endangered  by  termites  should  be 
frequently  inspected,  (g)  It  is  often  best  to  replace  woodwork 
with  stone  or  metal. 


FIG.  64. — Termites  (Termes  flavipes).  Queen,  nymph  of  winged  femaley 
worker,  and  soldier.  (Enlarged.)  Marlatt  (U.  8.  Division  of  Entomology, 
Circular  No.  50). 

Summary. — Adult  termites  are  the  principal  terrestrial  wood- 
borers  that  attack  woods  in  construction.  Termites  are  occasion- 
ally active  in  the  North,  but  are  often  exceedingly  active  in  the 
tropics  and  semi-tropics.  It  is  safest  to  replace  wood  by  iron  or 
stone  wherever  termites  are  known  to  be  unduly  active. 

THE  CARPENTER-BEE  (Xylocopavirginica). — The  carpenter- 
bee,  which  resembles  the  ordinary  bumble-bee  in  size  and  appear- 
ance, is  equipped  with  powerful  jaws,  and  often  attacks  telegraph 
poles,  fence  posts,  and  house  timbers.  The  tunnels  thus  formed 
may  be  one  foot  or  more  in  length,  and  are  used  by  the  bees  as 
nesting  places.  Some  wasps  attack  wood. 

THE  LARGE  CARPENTER  ANT  (Camponotus  herculeanus 
pennsylvanicus) . — As  distinct  from  the  termite  this  is  a  true  ant, 
and  like  other  ants -it  develops  with  complete  metamorphosis.  It 
seldom  attacks  sound  trees,  but  does  often  attack  some  of  those 


324 


ORGANIC  STRUCTURAL  MATERIALS 


that  have  been  wounded  or  are  diseased,  and  also,  sometimes, 
attacks  woods  in  construction.  McCook  states  that  carpenter 
ants  were  responsible  for  "at  least  one  accident"  that  occurred 
in  connection  with  the  wooden  trestle  bridges  formerly  used  by 
the  Pennsylvania  Railroad  Company.1 

Ants  offer  one  of  the  most  perfect  illustrations  of  communistic  society. 
The  State  declares  war,  provides  food,  cares  for  the  children,  and  owns 
all  the  property.  Patriotism,  loyalty,  courage,  and  never-failing  indus- 
try are  exhibited.  War,  pillage, 
slavery,  and  disregard  for  the 
rights  of  other  communities  pre- 
vail. There  are  many  species  of 
ants,  and  each  one  is  character- 
ized by  some  peculiarity.  Some 
are  road  builders;  others  live  in 
large  mounds;  and  some  bore  in 
decayed  trees .  Most  ants  tunnel . 

METHODS    OF    PROTECTION 

Injury  from  insects  can- 
not be  completely  controlled. 
Man  has  not  yet  succeeded 
in  eliminating  a  single  species 
of  insects.  But  as  distinct 
from  this,  the  enormous  losses 
that  now  result  from  this  cause 
would  be  greater  than  they 
are  if  man  had  remained  in- 
active. 

It  is  estimated  that  losses  due 
to  the  Hessian  fly  have  been  re- 
duced over  $100,000,000  annually,  and  also  that  the  rotation  of  corn  with 
oats  and  other  crops  has  reduced  the  damage  done  by  root  worms  to  the 
corn  crop  of  the  Mississippi  Valley  about  $100,000,000  annually. 
$15,000,000  to  $20,000,000  are  saved  annually  by  protecting  apple 
trees  from  insects  by  means  of  sprays. 

Defensive  practice  is  almost  wholly  in  the  hands  of  foresters 
and  horticulturists  and  is  directed  toward  the  protection  of  trees. 
Engineers  seldom  attempt  to  protect  woodwork  from  insects  other 
than  termites,  and  the  methods  used  to  protect  wood  from  these 


FIG.  65.  Tunnel  of  carpenter-bee  in 
yellow-pine  grape-arbor  post,  New 
York  City. 


1  ''Nature's  Craftsman,"  McCook  (pp.  126,  127). 


PLATE  XV.     HIGH  POWER  SPRAYING  APPARATUS  IN  ACTION 


From    "Report   of  Field  Work  against  Gypsy  Moth  and  Brown-Tail  Moth,"  Rogers  & 
Burgess  (United  States  Bureau  of  Entomology,  Bulletin  87). 

(Facing  page  324.) 


MARINE  AND  TERRESTRIAL  WOODBORERS     325 

insects  resemble  those  used  to  protect  it  from  marine  woodborers 
and  from  rot.  The  value  of  birds  as  defensive  agents  against 
insects  is  beyond  estimate.  When  birds  are  destroyed  insects 
increase  proportionately.  This  value  of  birds  in  maintaining 
the  balance  set  by  nature  should  be  recognized  by  all.  Some 
insects  that  prey  upon  other  insects  should  be  noted  also.  Some 
of  these  helpful  insects  directly  destroy  those  that  are  harmful, 
while  others  destroy  the  harmful  insects  indirectly  by  depositing 
their  eggs  on,  or  in  their  bodies.  These  predaceous  and  parasitic 
insects  are  natural  agents  of  great  value  in  insect  control. 


CHAPTER  XIII 
PROTECTIVE  METHODS — SEASONING 

The  term  seasoning  refers  to  certain  processes  designed  to  re- 
move water  from  woods.  Woods  dry,  shrink,  and  otherwise 
improve  by  these  processes. 

Improvement  Caused  by  Drying. — The  influence  of  moisture 
upon  wood  has  already  been  considered.1  Dry  wood  is  stronger 
than  green  wood  and  much  less  liable  to  decay.  All  woods  should 
be  shrunk  before  they  are  finally  placed  in  position. 

Improvement  Caused  by  Alteration. — Experience  shows  that 
other  changes  take  place  when  woods  are  seasoned.  Von 
Schrenk  believes  that  albuminous  substances,  and  possibly 
tannin,  resins,  and  other  incrusting  materials  are  altered  or 
recombined  during  these  processes.2  The  reasons  are  not  clear, 
but  the  facts  are  that  additional  changes  do  take  place  and  that 
they  are  of  such  a  nature  as  to  suggest  the  changes  that  take 
place  in  fruits  when  they  are  "  cured." 

It  is  often  hard  to  season  wood  without  injuring  it  somewhat. 
This  is  because  of  (1)  irregularities  that  exist  in  the  arrangement 
of  the  wood-elements,  and  (2)  irregularities  that  exist  in  the  dis- 
tribution of  the  moisture;  as,  for  example,  the  difference  in  the 
amount  of  moisture  in  the  sapwood  and  in  the  heartwood  of  a 
green  log.  It  is  easy  to  dry  wood,  but  it  is  not  always  easy  to  dry 
it  so  that  every  part  will  shrink  together.  All  methods  are  not 

1  See  Index. 

2  "Seasoning  of  Timber"  (United  States  Bureau  of  Forestry,  Bulletin  No. 
41,  p.  9). 

REFERENCES. — "Timber,"  Roth  (United  States  Division  of  Forestry, 
Bulletin  No.  10,  1895);  "  Seasoning  of  Timber,"  von  Schrenk  (United 
States  Bureau  of  Forestry,  Bulletin  No.  41,  1903);  "Kim-Drying  Hardwood 
Lumber,"  Dunlap  (United  States  Forest  Service,  Circular  No.  48,  1906); 
"Principles  of  Drying  Lumber  at  Atmospheric  Pressure,"  Tiemann  (United 
States  Forest  Service,  Bulletin  No.  104,  1912).  See  also  catalogues  of  the 
B.  F.  Sturtevant  Company,  the  Morton  Dry  Kiln  Company,  the  Standard 
Dry  Kiln  Company,  the  American  Blower  Company,  etc.  "The  Theory  of 
Drying,  etc.,"  Tiemann  (United  States  Department  of  Agriculture,  Bulletin 
No.  509,  March,  1917).  i( 

326 


PRESERVATION  OF  WOOD— SEASONING 


327 


suitable  for  all  woods.     Judgment  and  experience  are  required  to 
select  the  proper  method  in  any  particular  case. 

Three  groups  of  processes  are  employed  to  season  woods. 
They  are  natural-seasoning,  water-seasoning,  and  kiln-seasoning. 

NATURAL  SEASONING. — Just  as  certain  fruits  will  either 
cure  or  rot,  according  to  the 
way  in  which  they  are  exposed 
to  the  weather,  so,  also,  will 
certain  woods.  When  woods 
are  exposed  under  certain 
conditions  in  the  open  air, 
water  is  expelled  and  the 
changes  that  have  been  de- 
scribed take  place. 

The  details  of  exposure  are 
important.     A  few  woods  do 


FIG.  66.— Close-piling.     This   en- 
courages rot. 


well  under  almost  all  con- 
ditions, but  the  rule  is  that 
close  piling  and  contact  with  the  ground  encourage  rot.  Tim- 
bers should  be  raised  from  the  ground  and  should  be  so  piled 
that  the  air  can  circulate  between  them  and  they  should  re- 

main in  these  positions  during 
intervals  that  depend  upon 
their  shapes  and  sizes. 

While  it  is  often  assumed 
that  the  best  results  are  those 
obtained  from  natural  sea- 
soning, it  should  be  remem- 
bered that  the  best  results 
are  not  invariably  thus  ob- 
tained. The  pieces  within  a 
pile  may  be  well  seasoned, 


FIG.  67.- 


permits 


and  checked  from  having 
dried  too  rapidly.  From  two  to  four  years  must  often  pass  be- 
fore woods  are  completely  dried  by  the  natural  method.  It  is 
expensive  to  hold  stock  so  long,  and  it  is  dangerous  because  of 
fires.  However,  wood  is  normally  improved,  even  although 
the  process  is  not  carried  through  to  the  end. 

The   extreme   form   of   natural   seasoning  is  practiced  with 
pieces  intended  for  musical  and  mathematical  instruments,  and 


328  ORGANIC  STRUCTURAL  MATERIALS 

wood  engravings.  On  the  other  hand,  most  railway  ties  and 
other  large  construction  pieces  receive  a  minimum  of  attention. 
It  seldom  happens  that  these  large  pieces  are  completely  sea- 
soned; but  the  improvement  that  takes  place  while  they  are 
piled  waiting  for  use  is  ordinarily  very  great,  and,  with  this  in 
view,  such  pieces  should  be  piled  loosely  so  that  the  air  can  cir- 
culate between  them. 

Natural  seasoning  requires  so  much  time  that  it  is  usually 
combined  with  some  other  method.  Before  woods  are  thus 
seasoned  they  are  often  soaked  in  water;  and  sometimes  drying 
commenced  by  this  method  is  completed  in  a  kiln.  Natural 
seasoning,  air  seasoning,  and  yard-drying  mean  the  same. 

WATER  SEASONING. — Logs  are  often  stored  under  water. 
The  tendency  to  crack  that  exists  when  they  are  exposed  to  the 
hot  sun,  and  the  danger  from  insects  and  from  rot,  are  counter- 
acted as  long  as  they  remain  thus  submerged. 

Woods  keep  safely  under  water,  and,  at  the  same  time,  undergo 
changes  that  render  them  more  durable  after  they  have  been 
removed  from  the  water.  They  dry  rapidly  when  brought  again 
into  contact  with  the  air,  and  are  then  durable  in  proportion  as 
they  have  been  washed  by  the  water.  Water  seasoning  is 
usually  combined  with  natural  seasoning. 

The  water  acts,  first  by  excluding  the  air,  and  second  by  leach- 
ing out  impurities.  There  is  no  reason  why  wood  should  ever 
decay  while  it  remains  under  water.  The  softening  or  physical 
disintegration  that  may  eventually  take  place  is  not  decay. 
Logs  are  sometimes  found  buried  deep  in  the  mud  of  swamps. 
Pieces  cut  from  such  logs  are  often  particularly  prized  because 
in  the  course  of  immersion  they  have  been  so  thoroughly  cleansed 
and  rendered  durable,  and  also  because  they  have  lost  much  of  the 
natural  tendency  to  warp. 

KILN  SEASONING. — Kiln  seasoning  originated  with  at- 
tempts to  prevent  warping  and  checking  in  special  pieces.  In  the 
United  States,  nearly  all  hardwoods,  save  those  in  large  con- 
struction pieces,  are  now  cured  by  this  method.  Drying  pro- 
ceeds rapidly  and  details  can  be  controlled  in  kilns  as  they  cannot 
be  in  natural-seasoning  or  in  water-seasoning. 

There  are  many  details  and  combinations,  but  the  factors  that 
influence  design  and  operation  in  all  cases  are  temperature,  mois- 
ture, and  circulation. 


PRESERVATION  OF  WOOD— SEASONING  329 

Temperature— Heat  may  be  dry  or  wet.  In  both  cases,  high  tem- 
peratures should  be  avoided.  Dry  heat  in  excess  of  two  hundred  and 
twelve  degrees  is  sufficient  to  expel  some  of  the  volatile  constituents  of 
the  wood,  which  then  becomes  weak  and  brittle.  The  equivalent  of 
this  temperature  in  moist  heat  is  not  known.  Temperatures  of  from 
one  hundred  degrees  to  one  hundred  and  twenty  degrees  Fahrenheit 
are  used  in  connection  with  green  oak  and  some  other  difficult  woods, 
while  temperatures  of  from  one  hundred  and  sixty  degrees  to  one  hun- 
dred and  eighty  degrees  Fahrenheit  are  employed  with  pine  and  cedar. 

The  temperature  of  the  entire  charge  must  be  raised  to  a  point  at 
which  the  drying  is  to  take  place.  The  surface  of  wood  heated  in  warm, 
dry  air  is  liable  to  shrink  before  the  heat  has  penetrated  and  acted  upon 


FIG.  68. — A  kiln  for  drying  wood. 

the  moisture  that  is  within.  Wet  heat  or  steam  adds  to  the  moisture 
but  assists  because  it  keeps  the  surface  soft  and  swollen  until  the  heat 
has  penetrated  to  the  interior. 

Moisture. — Natural  moisture  or  sap  must  be  distinguished  from 
moisture  that  may  be  absorbed  after  the  tree  has  been  cut  down.  Most 
of  the  natural  moisture  is  in  the  outer  sapwood  and  this  moisture  is 
often  retained,  or  even  added  to,  with  advantage,  so  that  the  outer  wood 
will  not  shrink  before  the  heat  has  penetrated  to  the  moisture  further  in. 
This  is  particularly  necessary  in  the  case  of  oaks  and  other  woods  char- 
acterized by  complex  cellular  arrangements. 

Ability  to  season  woods  successfully  in  kilns  depends  upon  ability 
to  manipulate  the  moisture.  Heat,  circulation,  and  the  kilns  themselves 
are  designed  or  directed  with  this  end  in  view.  Some  processes  include 
the  addition  of  steam  while  others  use  only  the  moisture  that  has  been 
evaporated  from  the  wood.  In  other  processes  the  moisture  from  the 
wood  is  removed  by  condensation  upon  the  surfaces  of  pipes  filled  with 
cold  water.  Moisture  is  sometimes  introduced  by  piling  snow  upon 
the  lumber  as  it  enters  the  "greenwood  ends"  of  the  kilns.  Pieces 
must  be  piled  so  as  to  facilitate  the  escape  of  the  moisture. 

Circulation. — The  air  within  a  kiln  does  not  remain  motionless.  On 
the  contrary,  it  moves  naturally  because  of  the  heat,  or  else  the  move- 
ment is  induced  by  means  of  fans,  and,  in  both  cases,  drying  may  be 


330 


ORGANIC  STRUCTURAL  MATERIALS 


hastened  or  retarded  by  hastening  or  retarding  the  circulation  of  the 
air  currents.  Air  currents  may  pass  in  at  the  bottom  and  out  through 
the  sides  of  the  kilns,  or  they  may  pass  through  the  kilns  from  one  end 
to  the  other. 

Forms  of  Kilns. — The  principal  features  of  all  kilns  are  (1) 
the  drying  chambers  in  which  the  wood  is  stored,1  (2)  the  fur- 
naces for  heating  air  or  making  steam,  and  (3)  the  devices  for 
causing  the  air  to  circulate  within  the  drying  chambers. 

There  are  kilns  within  which  charges  remain  stationary,  and 
others  within  which  charges  move  through  from  end  to  end. 


FIG.  69. — Interior  of  a  drying  chamber. 

When  the  wood  remains  stationary,  in  what  is  known  as  a  "  charge 
kiln"  or  " apartment-kiln,"  the  moisture  in  the  air  is  removed 
little  by  little,  and  the  mass  is  finally  exposed  to  a  current  of 
warm,  dry  air.  When  the  charge  moves  forward,  in  what  is 
known  as  a  "  progressive-kiln/'  it  advances  through  an  air- 
current  that  contains  most  moisture  near  the  entrance  or  "green- 
wood end"  and  least  moisture  at  the  other  extremity  where  the 
wood  emerges. 

Kilns  are  also  grouped  according  to  the  origin  of  the  draft, 
which  may  be  natural,  if  caused  by  pipes  or  radiators  placed 
beneath  the  drying  chambers;  or  it  may  be  forced  if  the  draft, 
heated  outside  the  kiln,  is  forced  in  by  a  fan.  As  stated  already, 

1  Drying  chambers  are  from  fifteen  feet  to  one  hundred  and  fifty  feet  in 
length  and  from  ten  feet  to  thirty  feet  in  width.  They  are  usually  built  of 
wood,  but  may  be  built  of  brick,  or  of  concrete,  as  shown  in  the  preceding 
picture. 


PRESERVATION  OF  WOOD— SEASONING 


331 


the  air  currents  may  pass  in  at  the  bottom  and  out  through  the 
sides  of  the  kilns,  or  they  may  pass  through  from  end  to  end. 

Kilns  designed  for  natural  draft  are  often  known  as  "moist- 
air  kilns,"  and  those  designed  for  forced  draft  as  "  hot-blast 
kilns,"  but  these  names  refer  to  details  of  operation,  rather  than 

-t-r 


FIG.  70. — A  scheme  for  a  radiator  kiln. 

to    methods    of    construction,    since    moist    air    may    be    used 
in  kilns  of  either  kind,  regardless  of  the  source  of  the  draft. 


FIG.  71. — A  scheme  for  a  blower  kiln. 

Natural-draft  kilns  and  forced-draft  kilns  are  also  sometimes 
referred  to  as  " radiator-kilns"  and  " blower-kilns "  respectively. 

A  scheme  for  a  radiator  or  moist-air  kiln  designed  for  progressive 
operation  is  shown  in  the  picture.  The  pieces  that  are  to  be  seasoned 
are  arranged  upon  trucks,  which  are  then  rolled  into  the  kiln  until  it  is 


332  ORGANIC  STRUCTURAL  MATERIALS 

full.  After  a  sufficient  time  in  the  kiln,  one  truck  with  its  charge  is 
removed  from  the  "  dry-wood  end,"  the  others  are  moved  forward,  and 
a  new  charge  is  admitted  at  the  "greenwood  end"  of  the  kiln.  The 
ventilator  shaft  at  the  right  is  often  dispensed  with.  The  general  direc- 
tion followed  by  the  air  currents  is  shown  by  the  arrows. 

A  scheme  for  a  blower-kiln  is  also  shown.  The  humidity  is  main- 
tained by  using  the  same  air  repeatedly.  The  saturated  air  drawn 
from  the  "greenwood  end"  at  the  left  of  the  picture,  deposits  part  of 
the  moisture  upon  the  cold  water  coils  located  at  the  left  of  the  fan, 
The  air  then  passes  on  through  the  fan  and  is  re-heated  by  the  steam 
pipes  toward  the  right.  The  air  is  relatively  dry  and  warm  as  it  re-enters 
the  dry  end  of  the  kiln.1 

Operation. — The  several  parts  of  the  process  employed  within 
a  kiln  of  any  kind  may  be  grouped  as  they  relate  (1)  to  prepara- 
tion and  (2)  to  drying.  First,  the  temperature  of  the  charge 
must  be  raised  to  the  point  at  which  the  drying  is  to  take  place, 
while  the  surfaces  of  the  pieces  that  make  up  the  charge  remain 
or  are  rendered  soft  and  permeable.  Second,  the  drying  is 
forced  by  means  of  the  draft,  but  at  such  a  rate  that  the  moisture 
from  within  the  pieces  can  move  out  fast  enough  to  replace  the 
moisture  that  escapes  from  their  surfaces. 

Preparation. — The  charge  or  apartment  kiln  both  prepares  and  then 
dries  the  wood  before  it  is  removed.  Once  within  this  kiln  the  wood  is 
not  removed  until  the  process  is  completed.  In  the  progressive  system 
the  wood  is  sometimes,  but  not  always,  prepared  before  it  is  admitted 
to  the  drying  chamber.  The  auxiliary  kiln,  that  is  here  sometimes  used, 
should  be  placed  as  near  as  possible  to  the  greenwood  end  of  the  prin- 
cipal kiln  so  that  the  charge  will  not  be  unduly  chilled  during  transfer. 

Drying. — The  draft  must  be  held  back  until  the  heat  has  penetrated 
within  the  pieces.  Even  then,  it  must  not  be  forced  unduly,  or  the 
surface  moisture  will  escape  too  rapidly,  and  cause  the  surface  wood  to 
shrink  before  that  inside  has  had  time  to  dry.  Case-hardening,  honey- 
combing, checking,  warping,  or  twisting  may  then  result. 

Difficulties. — In  kilns,  where  drying  is  hastened,  the  difficulties 
that  have  been  mentioned  in  connection  with  slower  methods  of 
seasoning  become  more  pronounced.  The  situation  has  been 
expressed  as  follows  :2 

"In  drying  chemicals  or  fabrics,  all  that  is  required  is  to  provide  heat 
enough  to  vaporize  the  moisture  and  circulation  enough  to  carry  off  the 

\From  United  States  Forest  Service;  Circular  No.  48. 
2  "Kiln-Drying  Hardwood  Lumber,"  Dunlap  (United  States  Forest  Serv- 
ice, Circular  No.  48,  p.  5.). 


PRESERVATION  OF  WOOD— SEASONING  333 

vapor,  and  the  quickest  and  most  convenient  means  to  these  ends  may 
be  used.  In  drying  wood,  whether  in  the  form  of  standard  stock  or 
finished  product,  the  application  of  the  requisite  heat  and  circulation 
must  be  carefully  regulated  throughout  the  entire  process,  or  warping 
and  checking  are  almost  certain  to  result.  Moreover,  wood  of  different 
shapes  and  thicknesses  is  very  often  differently  affected  by  the  same 
treatment.  Finally,  the  tissues  composing  the  wood,  which  vary  in 
form  and  physical  properties  and  which  cross  each  other  in  regular 
directions,  exert  their  own  peculiar  influence  upon  its  behavior  during 
drying.  With  our  native  woods,  for  instance,  summer  wood  and  spring 


FIG.  72. — Auxiliary  kiln  for  preliminary  treatment. 

wood  show  distinct  tendencies  in  drying,  and  the  same  is  true  in  less 
degree  of  heartwood  as  contrasted  with  sapwood.  Or,  again,  pro- 
nounced medullary  rays  further  complicate  the  drying  problem.  Plain 
oak  and  quartered  oak  require  different  treatment.  Even  in  mahogany 
and  similar  tropical  woods,  which  are  outwardly  more  homogeneous, 
various  kinds  of  tissues  are  differentiated." 

The  presence  of  knots,  windshakes,  frostshakes,  and  other 
defects  add  to  the  problem,  which  is  to  dry  without  distortion 
rather  than  simply  to  dry.  The  comparatively  simple  cellular 
structure  of  coniferous  woods  makes  it  easier  to  dry  the  woods  of 
that  series.  The  broadleaf  woods  as  a  group  are  more  difficult, 
and  some  of  them,  such  as  the  oaks,  are  particularly  hard  to  dry. 


334  ORGANIC  STRUCTURAL  MATERIALS 

Time  Required. — The  time  required  to  kiln-season  lumber 
depends  upon  the  sizes,  shapes,  and  species  of  the  individual 
pieces.  Some  operators  dry  one-inch  white  oak  planks  in  four 
or  five  days,  while  others  require  one  or  two  weeks  for  the  same 
woods,  and  still  others  need  twice  as  long.  Plain  oak  and 
mahogany  dry  with  about  the  same  speed;  these  woods  require 
less  time  than  quartered  oak,  and  longer  than  ash,  birch,  and 
basswood. 

PROTECTION  OF  SEASONED  WOODS.— Dry  woods 
should  remain  dry.  Woods  suffer  if  their  cell  structures  expand 
and  contract  too  frequently.  The  cell  structures  may  remain 
healthy,  but  they  separate  more  easily  from  one  another,  and 
eventually  the  piece  as  a  whole  is  weakened.  The  influence  of 
moisture  upon  the  fungi  that  cause  disease  will  be  remembered. 
Seasoned  woods  that  are  to  be  exposed  to  the  weather  should  be 
protected  by  coatings  applied  to  their  surfaces,  or  by  antiseptics 
introduced  within  them. 


CHAPTER  XIV 

PROTECTIVE  METHODS — INTERNAL  TREATMENT 
PRESERVATIVE  COMPOUNDS  APPLIED  WITHIN  WOODS 

Preservative  compounds  are  applied  within  woods  to  produce 
results  of  several  kinds.  Sometimes,  the  object  is  to  increase 
resistance  to  decay;  sometimes,  it  is  to  repel  the  attacks  of 
teredos  and  other  live  woodborers,  and  sometimes,  the  object 
is  to  retard  fires.  Preservatives  within  woods  remain  where 
paints  on  the  outside  would  soften  or  be  rubbed  away.  Paints 
would  fail  if  applied  to  woods  used  in  marine  positions  or  in  rail- 
way ties,  whereas  preservatives  injected  within  woods  have  suc- 
ceeded in  such  positions. 

Preservative  chemicals  were  first  applied  within  woods  in 
England.  The  diminished  supply  of  wood,  and  the  early  rotting 
of  their  wooden  ships,  caused  the  English  to  practice  within  this 
field  more  than  one  hundred  years  ago.  The  beginning  of  real 
activity,  however,  was  connected  with  the  development  of  rail- 
ways (1830-1840). 

REFERENCES. — "Antiseptic  Treatment  of  Timber,"  Boulton  (Proceedings 
Institution  of  Civil  Engineers,  London,  1884);  "The  Preservation  of  Tim- 
ber," Report  of  Committee  (Transactions  American  Society  of  Civil  Engi- 
neers, 1885);  "Wood  Preservation,"  Flad  (United  States  Forest  Service, 
Bulletin  No.  1,  1887);  "Preservation  of  Railroad  Ties,"  Curtis  (Transactions 
American  Society  of  Civil  Engineers,  Vol.  XLII,  1899);  "Proposed  Method 
of  Preservation  of  Timber  with  Discussion,"  Kummer  (Transactions  Ameri- 
can Society  of  Civil  Engineers,  Vol.  XLIV,  1900);  "Hand-book  of  Timber 
Preservation,"  Samuel  M.Rowe  (Author's  Edition,  1900);  "Preservation  of 
Railway  Ties  in  Europe,"  Chanute  (Transactions  American  Society  of  Civil 
Engineers,  Vol.  XLV,  1901);  "Timber  Tests  and  Discussions"  (Transactions 
American  Society  of  Civil  Engineers,  Vol.  LI,  1903) ;  "  Decay  of  Timber,"  von 
Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin  No.  14);  "Recent 
Progress  in  Timber  Preservation,"  von  Schrenk  (United  States  Department 
of  Agriculture,  Yearbook,  1903);  "The  Inspection  of  Treatment  for  the 
Protection  of  Timber  by  the  Injection  of  Creosote  Oil,"  Stanford  (Transac- 
tions American  Society  of  Civil  Engineers,  Vol.  LVI,  1905);  "The  Preserva- 
tion of  Structural  Timber,"  Weiss  (McGraw-Hill  Book  Co.,  1915);  Bulletins 
of  American  Railway  Engineering  Association;  "Handbook"  (1916)  and 
other  Publications  of  the  American  Wood  Preservers  Association;  also,  other 
Publications  of  United  States  Department  of  Agriculture;  etc.,  etc. 

335 


336  ORGANIC  STRUCTURAL  MATERIALS 

The  field  of  wood  preservation  has  not  been  occupied  to  the 
same  extent  in  the  United  States  as  in  Europe.  Woods  have 
been  more  plentiful  in  the  United  States,  where,  consequently, 
the  demands  for  construction  have  hitherto  been  along  extensive, 
instead  of  intensive,  lines. 

A  study  of  the  subject  of  wood  preservation  from  a  local  stand- 
point was  inaugurated  by  the  American  Society  of  Civil  Engi- 
neers in  1880,  and  the  report  issued  by  this  Society  five  years 
later  is  yet  recognized  as  text.  The  study  thus  commenced  was 
continued  by  the  United  States  Department  of  Agriculture, 
which,  having  organized  a  Division  of  Forestry,  issued  its  first 
bulletin  in  1887.  The  situation  in  the  United  States  today  sug- 
gests the  situation  as  it  was  in  England  some  years  ago;  save 
that  English  engineers  were  obliged  to  learn  from  the  beginning, 
whereas  Americans  have  profited  from  successes  and  failures  of  a 
century  of  European  practice. 

The  price  of  wood  is  advancing  in  the  United  States;  and, 
dependent  upon  this,  the  practice  of  wood  preservation  is  rapidly 
becoming  more  general.  Prior  to  1901  only  fifteen  timber  pre- 
serving plants  were  in  operation,  while,  during  the  six  successive 
years,  this  number  was  increased  to  fifty.1  Nearly  ten  per  cent, 
of  the  total  number  of  railway  ties  recorded  as  having  been  pur- 
chased during  1905  received  preservative  treatment  of  some  kind. 

A  French  authority  states  that  one  hundred  and  sixty-seven 
wood-preserving  substances  or  processes  were  tried  or  introduced 
prior  to  1874,2  while  Weiss  enumerates  two  hundred  and  sixty- 
eight  patents  granted  in  the  United  States  alone  in  this  field  since 
that  year.3  Most  processes  and  chemicals  included  in  these  and 
other  lists  have,  however,  been  abandoned.  In  1885,  the  Com- 
mittee of  the  American  Society  of  Civil  Engineers  reported  fully 
upon  only  four  preservatives  and  processes;  and,  in  spite  of  the 
time  that  has  elapsed  since  this  report  was  rendered,  these  four 
are  yet  regarded  as  the  most  important. 

It  is  hardly  probable  that  many  methods  now  unknown  will  be 
successfully  introduced  in  the  future,  because  years  must  elapse 
before  the  efficiency  of  a  material  or  a  method  can  be  proved  by 


(United  States  Forest  Service,  Circular  No.  43,  p.  6).  Weiss 
enumerates  one  hundred  and  ten  wood-preserving  plants  as  existing  in  the 
United  States  in  1914  (pp.  255-258). 

2  "Traite  de  la  conservation  desbois,"  Paulet  (Paris,  1874). 

3  "Preservation  of  Structural  Timber,"  Weiss  (1915). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  337 

actual  tests.  Woods  are  more  costly  and  chances  less  war- 
ranted than  in  former  years.  As  distinct  from  the  development 
of  new  practices,  however,  it  is  probable  that  in  the  future  more 
attention  will  be  given  to  perfecting  practices  already  known,  and, 
that  results  obtained  in  the  United  States,  will  ultimately  be 
more  uniformly  satisfactory  than  at  the  present  time. 

The  subject  is  one  that  requires  attention  along  three  lines, 
namely:  the  materials  used  to  preserve  woods,  the  processes  used 
to  force  such  materials  into  the  woods,  and  the  woods  that  will 
best  receive  and  respond  to  the  preservative  materials  thus  used. 

PRESERVATIVE  MATERIALS 

Salt,  formaldehyde,  lime,  sulphate  of  iron,  tannin,  oils,  arsenic, 
and  many  other  substances  have  been  tried  or  considered  for 
preserving  woods.  Of  this  entire  series  copper  sulphate,  zinc 
chloride,  mercury  bichloride,  and  creosote,  either  separately  or 
in  combinations,  have  succeeded  best;  while  of  this  smaller  list, 
zinc  chloride  and  creosote  are  now  most  used.1 


irThe  following  list  is  taken  from  "Handbook  on  Wood  Preservation" 
(American  Wood  Preservers'  Association,  p.  27,  1916).  It  enumerates  some 
of  the  substances  which  have  been  proposed  as  means  of  protecting  wood 
against  destruction  by  fire,  fungi,  and  woodborers : 

Aluminum  sulphate  Petroleum  oils 

Animal  oils  Potassium  carbonate 

Barium  carbonate  Potassium  nitrate 

Barium  sulphate  Resins 

Borax  Sodium  carbonate 

Cedar  oil  Sodium  chloride 

Copper  sulphate  Sodium  fluoride 

Creosotes  (coal-tar,  Sodium  muriate 

water-gas-tar,  wood,  Sodium  sulphate 

petroleum)  Sulphuric  acid 

Crude  oil  Tannin 

Fish  oil  Tar 

Glue  Tartaric  acid 

Gums  (various)  Vegetable  oils 

Iron  sulphate  Wax 

Lime  hydrate  Whale  oil 

Linseed  oil  Zinc  chloride 

Magnesium  sulphate  Zinc  sulphate 
Mercuric  bichloride 
Molasses  and  low  syrups 


338  ORGANIC  STRUCTURAL  MATERIALS 

Wood  preservatives  may  be  divided  as  they  do,  or  do  not, 
dissolve  in  water.  First,  the  salts  of  metals  dissolve  in  water, 
and,  for  this  reason,  eventually  escape  if  used  where  it  is  wet; 
but  second,  creosote,  which  is  an  oily  mixture,  does  not  dissolve 
in  water.  Creosote  is  much  more  permanent  in  its  effects  than 
are  the  salts  of  metals.  It  should  be  remembered  that  the 
influence  of  any  chemical  may  continue  for  a  short  time  after 
the  removal  of  the  chemical. 

TANNIN  (CnHioOg). — Tannin  is  an  antiseptic  and  coagulant. 
Tannin  and  tannic  acid  are  the  same.1  Tannin  is  present  in 
parts  of  many  trees  and  doubtless  influences  the  natural  dura- 
bility of  woods.  It  is  used  in  the  preparation  of  leather,  as  well 
as  in  the  artificial  preservation  of  woods,  although,  in  the  latter 
case,  it  is  used  only  in  combination  with  other  substances. 

Tannin  serves  in  this  connection,  together  with  glue,  in  what 
are  known  as  the  "zinc  tannin  processes."  The  leather-like 
solids  which  result  during  these  processes  from  the  action  of  the 
tannin  upon  the  glue,  fill  up  the  pores  of  the  wood  and  retard  the 
escape  of  zinc  chloride,  which  is  soluble  in  water. 

COPPER  SULPHATE  (CuSO4.5H2O).— This  is  the  blue 
vitriol  of  commerce.  Chapman  experimented  with  wood  soaked 
in  copper  sulphate  as  early  as  1816.  Boucherie,  who  concerned 
himself  with  methods  for  forcing  preservatives  into  woods  rather 
than  with  the  preservatives  themselves,  after  employing  various 
antiseptics,  finally  pronounced  in  favor  of  copper  sulphate;  and 
in  consequence  of  this,  the  name  of  Boucherie  is  associated  with 
copper  sulphate  and  also  with  the  process  used  for  introducing  it 
into  wood.  Copper  sulphate  is  a  very  valuable  wood  antiseptic 
but  it  dissolves  readily  in  water  and  escapes  easily  from  the  wood. 
It  is  decomposed  when  brought  into  contact  with  iron.  Very 
little  of  it  is  now  used  in  wood  preservation  in  the  United  States. 

MERCURY  BICHLORIDE  (HgCl2).— The  application  of  mer- 
cury bichloride  in  wood  preservation  was  first  suggested  by 
John  Howard  Kyan  in  England  in  1833.  Mercury  bichloride 
is  the  most  active  of  all  wood  preservatives  in  use.  Very  small 
quantities  are  effective,  and  because  the  quantities  needed  are  so 
small  the  actual  cost,  although  considerable,  is  not  as  great  as  at 
first  appears.  It  dissolves  in  boiling  water,  and  once  within  the 

1  In  the  strictly  chemical  sense,  tannic  acid  is  not  a  true  acid,  but  an  anhy- 
dride of  an  acid,  belonging  to  the  class  of  phenols.  Tannin  is  therefore  the 
more  nearly  correct  name.  The  two  terms  refer  to  the  same  substance. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  339 

wood,  resists  the  actual  moisture  of  reasonably  dry  places  much 
longer  than  do  copper  sulphate  and  zinc  chloride.  On  the  other 
hand,  mercury  bichloride  attacks  iron;1  in  spite  of  the  small 
quantities  necessary  it  is  comparatively  costly,  and  it  is  very 
poisonous  to  human  beings.2 

ZINC  CHLORIDE  (ZnCl2). — Zinc  chloride,  which  is  obtained  by 
dissolving  metallic  zinc  in  hydrochloric  acid,  is  a  cheap  and  very 
good  wood  preservative,  its  toxic  effects  upon  wood-destroying 
fungi  being  about  equal  to  those  of  creosote ;  also  it  has  an  affinity 
for  wood  fiber  into  which  it  penetrates  to  a  considerable  depth. 
Its  chief  fault  is  that  it  attracts  water  and  dissolves  easily  in  it. 
Experience  shows,  however,  that  it  will  remain  in  timber  in 
reasonably  dry  locations  for  many  years.  It  cannot  be  used  in 
marine  constructions,  but  has  caused  railway  ties  which  would 
normally  fail  in  four  or  five  years  to  remain  sound  for  ten  or  more 
years.  Many  million  pounds  of  zinc  chloride  are  now  used 
annually  in  the  United  States  in  treating  wood. 

Zinc  chloride  is  the  cheapest  wood  preservative  practically 
available  in  this  country,  and  in  spite  of  defects  that  have  led 
most  European  railways  to  cease  using  it,  is  highly  regarded  as 
an  antiseptic  that  meets  some  temporary  American  conditions. 
Burnett  first  called  attention  to  the  value  of  zinc  chloride  as  a 
wood  preservative  in  1838. 

CREOSOTE.3 — The  name  creosote  applies  to  products  derived 

1  The  reaction  is  as  follows:  Fe  +  HgCl2  =  FeCl2  +  Hg. 

2  The  antidote,  when  this  active  poison  is  taken  into  the  stomach,  is  fresh 
milk  or  else  egg  water  made  by  dissolving  three  or  four  raw  eggs  in  one 
quart  of  water. 

3  REFERENCES. — "Coal-tar  and  Ammonia,"  Lunge;  "Causes  Underlying 
the  Limited  Production  of  Creosote  in  the  United  States"  (Forestry  and  Irri- 
gation, October,  1906,  pp.  482-484);  "Fractional  Distillation  of  Coal-tar 
Creosote,"  Dean  and  Bateman  (United  States  Forest  Service,  Circular  No. 
80);  "Quantity  and  Character  of  Creosote  in  Well-preserved  Timbers," 
Alleman  (United  States  Forest  Service,  Circular  No.  98);  "The  Analysis  and 
Grading  of  Creosotes"  (United  States  Forest  Service,  Circular  No.  112); 
"Volatilization  of  Various  Fractions  of  Creosote  after  their  Injection  into 
Wood,"  Teesdale  (United  States  Forest  Service,  Circular  No.  188);  "Modi- 
fication of  the  Sulphonation  Test  for  Creosote,"  Bateman  (United  States 
Forest  Service,  Circular  No.  191).    Other  Publications  of  the  United  States 
Forest  Service.     Manual,  1911,  and  other  Publications  American  Railway 
Engineering  Association.     Proc.  American  Wood  Preservers'  Association. 
Specifications  American   Telephone  and  Telegraph  Company.     "Coal-tar 
Distillation,"  Warnes  (D.  Van  Nostrand  Company,  1914).     "Preservation 
of  Structural  Timber,"  Weiss  (McGraw-Hill  Company,  1915). 


340 


ORGANIC  STRUCTURAL  MATERIALS 


from  water-gas  tar  and  wood;  but,  in  construction,  unless  other- 
wise noted,  it  now  refers  principally  to  a  mixture  distilled  from 
coal-tar.  Coal-tars  vary  and  the  mixtures  obtained  from  them 
during  distillation  vary  also.  It  is,  therefore,  particularly  un- 
fortunate that  there  can  be  no  chemical  formula  for  creosote. 
The  value  of  creosote  as  a  wood  preservative  was  suggested  by 
Bethell  in  1838.  Tar  oil,  heavy  oil  of  tar,  dead  oil  of  tar,  and 
coal-tar  creosote  are  different  names  for  the  same  material. 

Water-gas-tar  and  wood  creosotes  are  antiseptics,  but  their 
success  with  woods  is  not  to  be  compared  with  that  which  has 
followed  the  use  of  coal-tar  creosote.  Wood  creosote  has  a  sweet- 
ish, burning  taste,  with  an  odor  that  resembles  that  of  smoked 


FIG.  73. — Cross-section  of  pole,  showing  penetration  of  creosote. 

meat  or  fish.1  Beef  cured  in  wood-smoke  owes  much  of  its  flavor, 
as  well  as  its  durability,  to  the  influence  of  the  volatile  wood  creo- 
sote present  in  the  smoke.  All  creosote,  whether  made  from 
wood,  water-gas  tar,  or  coal-tar,  is  poisonous  to  human  beings. 

Coal-tar  creosote  stands  by  itself  among  the  wood  preserva- 
tives. The  others  dissolve  in  water,  but  creosote,  in  addition  to 
being  an  antiseptic,  is  nearly  insoluble  in  water.  Creosote  pre- 
vents rot,  and  also  protects  wood  from  the  attacks  of  terrestrial 
and  marine  woodborers.  The  salts  of  metals  do  not  materially 
lessen  the  porosity  of  wood,  but  creosote,  in  sufficient  quantities, 
fills  and  stiffens  within  the  cell-structures,  shuts  off  the  air,  with- 

1  For  references  with  regard  to  wood  creosote,  see  "  Report  on  Wood  Creo- 
sote Oil,"  Bixby  (United  States  Forestry  Bulletin  No.  1);  United  States 
Dispensatory;  "The  Preservation  of  Structural  Timber,"  Weiss  (p.  86). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  341 

out  which  fungi  cannot  live,  and  is  the  only  preservative  in  com- 
mon use  that  keeps  wood-fibers  dry. 

No  real  difference  of  opinion  exists  with  regard  to  the  value  of 
creosote,  the  use  of  which  depends  almost  entirely  upon  its 
availability  and  cost.  In  Europe,  where  creosote  is  compara- 
tively plentiful  and  cheap,  engineers  use  it  for  ties  and  in  almost 
all  wood-work  that  requires  preservation.  Americans  now  use  it 
to  prevent  rot  in  railway  ties,  mud  sills,  bridge  timbers,  and  pav- 
ing blocks,  and  to  protect  timbers  designed  for  marine  construc- 
tions from  teredos  and  limnoria.  Creosote  is  not  yet  used  as 
widely  in  this  country  for  ties  as  it  is  abroad,  but  its  use  as  a  tie 
preservative  is  increasing. 

As  manipulated  in  gas  works,  mineral  coal  yields  illuminating  gas, 
ammoniacal  liquid,  coal-tar,  and  coke.  Of  these,  the  tar,  which  is  a 
sticky  black  substance,  is  separated  by  distillations  conducted  between 
certain  temperatures,  into  (1)  light  oils,  that  is  oils  lighter  than  water, 
(2)  middle  oils,  (3)  heavy  oils,  that  is  oils  heavier  than  water,  and  (4) 
residue  or  pitch.  The  variable  mixture  obtained  during  the  third  dis- 
tillation is  called  creosote.  This  is  also  shown  on  the  diagram. 

Coal 


Gas  Ammoniacal  Tar  Coke 

Liquid 


Light  Oils  Middle  Oils         Heavy  Oils  or  Pitch 

Creosote 

The  list  that  follows,  although  incomplete,  is  sufficient  to  show  the 
complex  nature  of  coal-tar.1  As  a  matter  of  fact,  almost  two  hundred 
definite  chemical  compounds  can  be  separated  when  this  material  is 
subjected  to  destructive  distillation. 

When  coal-tar  is  submitted  to  distillation  and  rectification,  it  yields, 
among  others,  the  following  products  in  varying  proportions:1 

1.  Solids.     Naphthalene,    methyl-naphthalene,    acetyl-naphthalene 
diphenyl,   fluorene,    anthracene,   phenanthrene,  fluoranthene,  methyl- 
anthracene,  retene,  chrysene,  pyrene,  picene,  and  carbazol. 

2.  Liquids.     These  may  be  neutral  hydrocarbons,  acids,  ethers  of 
acids,  or  their  bases.     The  neutral  hydrocarbons  are  benzene,  toluene, 
methyl- toluene,  and  iso-xylene,  pseudocumene,  mesitylene,  and  cymene. 
The  acid  constituents  are  phenol,  orthocresol,  paracresol,  metacresol, 
phlorol,  rosolic  acid,  pyrocatechin,  and  creosote,  consisting  of  the  methyl 
ethers  of  pyrocatechin  and  its  homologues.     There  are  also  present, 

1  " Coal-tar  and  Ammonia,"  Lunge  (London)  United  States  Dispensatory; 
"Coal-tar  Distillation,"  Warnes  (D.  Van  Nostrand  Company,  1914). 


342  ORGANIC  STRUCTURAL  MATERIALS 

probably  in  combination  with  the  ammonia  of  the  ammoniacal  liquor, 
acetic,  butyric,  carbonic,  hydrocyanic,  sulphocyanic,  and  hydrosul- 
phuric  acids.  The  bases  are  ammonia,  methylamine,  ethylamine, 
phenylamine,  pyridine,  picoline,  lutidine,  collidine,  leucoline,  iridoline, 
cryptidine,  acridine,  coridine,  rubidine,  and  viridine. 

3.  Gases,  (a)  Illuminating  gases.  Acetylene,  ethylene,  propylene, 
butylene,  allylene,  crotonylene,  terene,  and  vapors  of  benzene,  styrolene, 
naphthalene,  methyl-naphthalene,  fluorene,  fluoranthene,  hexane,  hep- 
tane, and  octane.  (6)  Heating  and  diluting  gases.  Hydrogen,  marsh- 
gas  (methane),  carbon  monoxide,  (c)  Impurities.  Carbon  dioxide, 
ammonia,  cyanogen,  methyl-cyanide,  sulphocyanic  acid,  hydrogen  sul- 
phide, carbon  disulphide,  carbon  oxysulphide,  and  nitrogen. 

A  highly  prized  creosote  is  obtained  as  a  by-product  from  Newcastle 
coals  burned  in  the  vicinity  of  London.  This  creosote,  known  as 
"  London  oil,"  is  thick  and  heavy.  The  English  Midland  districts  pro- 
duce lighter  creosotes,  known  as  "country  oils."  German  creosote  is 
much  employed.  Much,  but  not  all,  good  creosote  now  used  in  this 
country  is  imported,  the  United  States  not  yet  having  met  the  demand 
for  this  product.  Also,  much  American  creosote  contains  an  excess  of 
naphthalene. 

Chemical,  physical,  and  physiological  results  are  brought  about  by 
the  several  ingredients  that  make  up  creosote.  The  wood  is  acted  upon 
by  the  carbolic  acid,  cresylic  acid,  and  associated  antiseptics.  The  cells 
are  treated  by,  or  filled  with  thick,  gummy  oil  and  naphthalene,  and  the 
creosote,  as  a  whole,  is  like  camphor  in  that  it  is  disliked  by  the  lower 
forms  of  life.1 

It  should  be  noted  that  creosotes  differ  in  their  behavior  when  under 
water.  Thick  London  oils  have  resisted  disintegration  in  marine  posi- 
tions for  forty  years,  while  some  American  creosotes,  applied  under  con- 
ditions that  prevail  in  some  parts  of  this  country,  have  failed  after  having 
been  exposed  to  the  action  of  water  for  a  few  months.2 

Creosote  should  be  thick,  since  thin  oil  is  correspondingly  less  stable. 
The  specific  gravity  should  be  greater  than  that  of  water.  The  influ- 
ence of  temperature  is  important,  because  some  of  the  ingredients,  relied 
upon  to  solidify  within  the  wood  when  they  have  cooled,  do  not  distil 
save  at  high  temperatures.  Tidy  wrote  upon  this  subject  as  follows:3 

1  "  Descriptions  of  Creosote  Best  Suited  for  Creosoting  Timber,"  Tidy 
(Appendix  7);  Boulton  on  "Antiseptic  Treatment  of  Timber,"  the  Institu- 
tion of  Civil  Engineers,  London;  "Coal-tar  and  Ammonia,"  Lunge  (Third 
Edition,  London,  pp.  473-477). 

2  "Changes  which  take  place  in  Coal-tar  Creosote  during  Exposure," 
von    Schrenk,    Fulks,    and    Kammerer    (American    Railway    Engineering 
Association,  Bulletin  No.  93,  November,  1907). 

3  "Antiseptic  Treatment  of  Timber,"  Boulton  (The  Institution  of  Civil 
Engineers,  London,  p.  51). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  343 

"Believing  strongly  as  I  do  in  the  value  of  those  constituents  of  the  oil 
that  are  the  most  difficult  to  volatilize,  I  have  deemed  it  right  to  sug- 
gest a  clause  to  the  effect  that  the  creosote  shall  contain  at  least  25  per 
cent,  of  matters  that  distil  over  at  about  600  degrees  Fahrenheit/'1 

The  ingredients  or  groups  of  ingredients  in  coal-tar  creosotes  that  are 
thought  in  the  United  States  to  exert  much  influence  in  wood  preserva- 
tion are  light  oils,  naphthalene,  anthracene,  or  anthracene  oils  and  tar 
acids.  French  engineers  attribute  much  to  the  presence  of  tar  acids, 
while  in  England,  credit  is  given  to  acridine.  Because  of  the  complex 
nature  of  creosote  and  difficulties  connected  with  analyses,  most  specifi- 
cations omit  mention  of  all  but  a  few  of  the  components  and  confine 
themselves  to  important  characteristics  and  reactions  that  indicate  the 
genuineness  of  creosote  as  a  whole.2 

Mixed  Coal-tar  Creosotes. — Pine  resin  has  been  used  to  thicken  creosote 
designed  for  the  treatment  of  paving  blocks.3  Coal-tar  is  often  mixed 
with  pure  creosote,  the  defense  being  that  the  supply  of  pure  creosote 
is  insufficient.  Other  materials  or  mixtures  are  also  used  with  pure 
creosote.  It  is  needless  to  say  that  when  pure  coal-tar  creosote,  free 
from  the  mixture  of  other  substances,  is  specified  that  creosote  only 
should  be  employed. 

The  fact  that  creosote  is  so  variable  renders  the  more  neces- 
sary some  form  of  specification  or  control.  It  is  unfortunate  that 
some  compounds  yet  sold  as  creosote  have  so  little  to  commend 
them  beyond  the  name,  since  failures  during  this  more  or  less  for- 
mative period  tend  to  retard  the  use  of  the  legitimate  mixture. 

The  properties  of  creosote  are  of  vital  importance.  It  should 
not  be  forgotten,  however,  that  there  are  other  factors  that  exert 
an  equal  influence  upon  the  preservation  of  wood  by  creosote. 
The  method  of  application  is  one  of  these  factors.  This  should 
be  such  that  deep  impregnation,  and  the  wide  diffusion  of  the 
creosote,  particularly  through  the  outer  parts  of  the  timber, 
result.  A  poor  quality  of  creosote  well  injected  may  yield  better 
results  than  a  good  quality  of  creosote  poorly  injected. 


1  Report  of  Tidy  (Boulton  on  "Antiseptic  Treatment  of  Timber,"  the 
Institution  of  Civil  Engineers,  London,  p.  51). 

2  About  55,000,000  gallons  of  creosote  were  used  in  the  wood-preserving 
plants  of  the  United  States  during  the  year  1908.     Of  this  amount,  about 
thirty  per  cent,  was  produced  in  this  country,  while  the  balance,  about 
seventy  per  cent.,  was  imported  principally  from  England,  Germany,  and 
Canada. 

3  See  Creo-Resinate  Process. 


344  ORGANIC  STRUCTURAL  MATERIALS 

Specifications  for  creosotes  are  of  two  kinds.  First,  certain 
properties  that  the  creosote  should  possess  are  specified;  and 
second,  methods  of  analysis  by  which  the  existence  of  these  prop- 
erties is  proved  or  the  properties  measured,  are  specified.  It  is 
needless  to  say  that  these  two  fields  depend  upon  one  another  and 
that  the  specifications  often  overlap. 

Specifications  for  Creosote. — Creosote,  once  purchased  largely 
on  faith,  is  now  bought  under  more  or  less  rigidly  enforced  speci- 
fications. Controlling  items  regardless  of  the  purposes  for  which 
the  oil  is  to  be  used  relate,  principally,  (1)  to  its  origin,  (2)  to  the 
limits  of  the  distillation  ranges,  (3)  to  its  specific  gravity,  and 
sometimes  (4)  to  the  percentages  of  several  constituents. 

(1)  The  origin  of  creosote  is  controlled  by  securing  it  from  reputable 
dealers.  (2)  The  determination  of  the  temperatures  between  which 
certain  fractions  of  the  original  bulk  distil  is  of  fundamental  importance, 
since  slight  changes  cause  considerable  variations  to  take  place  in  the 
results  of  the  analysis.  (3)  It  is  usually  specified  that  creosotes  should 
have  specific  gravities  of  from  101  to  112.  (4)  The  percentages  of  cer- 
tain components  as  tar  acids  and  naphthalene  are  sometimes  stated. 

English  practice  is  based  upon  the  Tidy  specification,1  which  is 
as  follows:  1.  " Creosote  should  be  completely  liquid  at  a  tem- 
perature of  100  degrees  Fahrenheit,  no  deposit  afterwards  taking 
place  until  the  oil  registers  a  temperature  of  93  degrees  Fahren- 
heit." 2.  "The  creosote  should  contain  at  least  twenty-five 
per  cent,  of  constituents  that  do  not  distil  over  at  a  temperature 
of  600  degrees  Fahrenheit."  3.  "  The  creosote  shall  yield  a  total 
of  eight  per  cent,  of  tar  acids."2 

Of  the  specifications  employed  in  the  United  States  those  pre- 
pared by  The  American  Railway  Engineering  Association,  The 
American  Telephone  and  Telegraph  Company,  and  The  United 
States  Forest  Service,  are,  on  the  whole,  most  important. 


1  See  Boulton  on  "Antiseptic  Treatment  of  Timber"  (The  Institution  of 
Civil  Engineers,  London,  p.  51).     Several  characteristic  European  speci- 
fications appear  with  Chanute's  paper  "Preservation  of  Railway  Ties  in 
Europe"  (Trans.  American  Society  of  Civil  Engineers,  Vol.  XIV). 

2  Some  American  and  foreign  specifications  are  shown  in  comparison  with 
one  another  in  a  paper  entitled,  "Changes  which  take  place  in  Coal-tar  Creo- 
sote during  Exposure,"   von   Schrenk,   Fulks  and  Kammerer    (American 
Railway  Engineering  Association,  Bulletin  No.  93,  November,  1907). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  345 

The  specification  prepared  by  The  American  Railway  Engi- 
neering Association  is  as  follows: 

Standard  Grade  of  Creosote  Oil  (Also  Known  as  No.  1  Oil). — The  oil 
used  shall  be  the  best  obtainable  grade  of  coal-tar  creosote;  that  is,  it 
shall  be  a  pure  product  obtained  from  coal-gas  tar,  or  coke-oven  tar, 
and  shall  be  free  from  any  tar,  oil  or  residue  obtained  from  petroleum 
or  any  other  source,  including  coal-gas  tar  or  coke-oven  tar;  it  shall  be 
completely  liquid  at  thirty-eight  (38)  degrees  Centigrade  and  shall  be 
free  from  suspended  matter;  the  specific  gravity  of  the  oil  at  thirty-eight 
(38)  degrees  Centigrade  shall  be  at  least  1.03.  When  distilled  by  the 
common  method — that  is,  using  an  eight  (8)  ounce  retort,  asbestos- 
covered,  with  standard  thermometer,  bulb  one-half  (^)  inch  above  the 
surface  of  the  oil — the  creosote,  calculated  on  the  basis  of  the  dry  oil, 
shall  give  no  distillate  below  two  hundred  (200)  degrees  Centigrade,  not 
more  than  five  (5)  per  cent,  below  two  hundred  and  ten  (210)  degrees 
Centigrade,  not  more  than  twenty-five  (25)  per  cent,  below  two  hundred 
and  thirty-five  (235)  degrees  Centigrade;  and  the  residue  above  three 
hundred  and  fifty-five  (355)  degrees  Centigrade,  if  it  exceeds  five  (5) 
per  cent,  in  quantity,  shall  be  soft.  The  oil  shall  not  contain  more  than 
three  (3)  per  cent,  water. 

In  addition  to  the  above  standard  specification,  the  two  following 
grades  can  be  used  in  cases  where  the  higher-grade  oil  cannot  be  pro- 
cured. It  should  be  understood  that  where  it  is  necessary  to  purchase 
grades  No.  2  and  No.  3  consideration  should  be  given  to  the  use  of  a 
greater  quantity  of  creosote  oil  per  cubic  foot. 

Specification  for  No.  2  Grade  Creosote  Oil. — The  oil  used  shall  be  the 
best  obtainable  grade  of  coal-tar  creosote;  that  is,  it  shall  be  a  pure 
product  obtained  from  coal-gas  tar,  or  coke-oven  tar,  and  shall  be  free 
from  any  tar,  oil  or  residue  obtained  from  petroleum  or  any  other  source, 
including  coal-gas  tar  or  coke-oven  tar;  it  shall  be  completely  liquid  at 
thirty-eight  (38)  degrees  Centigrade  and  shall  be  free  from  suspended 
matter;  the  specific  gravity  of  the  oil  at  thirty-eight  (38)  degrees  Centi- 
grade shall  be  at  least  1.03.  When  distilled  by  the  common  method — 
that  is,  using  an  eight  (8)  ounce  retort,  asbestos-covered,  with  standard 
thermometer,  bulb  one-half  (^)  inch  above  the  surface  of  the  oil — the 
creosote,  calculated  on  the  basis  of  the  dry  oil,  shall  give  not  more  than 
eight  (8)  per  cent,  distillate  below  two  hundred  and  ten  (210)  degrees 
Centigrade,  not  more  than  thirty-five  (35)  per  cent,  below  two  hundred 
and  thirty-five  (235)  degrees  Centigrade;  and  the  residue  above  three 
hundred  and  fifty-five  (355)  degrees  Centigrade,  if  it  exceeds  five  (5) 
per  cent,  in  quantity,  shall  be  soft.  The  oil  shall  not  contain  more 
than  three  per  cent,  water. 


346  ORGANIC  STRUCTURAL  MATERIALS 

Specification  for  No.  3  Grade  Creosote  Oil. — The  oil  shall  be  the  best 
obtainable  grade  of  coal-tar  creosote;  that  is,  it  shall  be  a  pure  product 
obtained  from  coal-gas  tar  or  coke-oven  tar  and  shall  be  free  from  any 
tar,  oil  or  residue  obtained  from  petroleum  or  any  other  source,  including 
coal-gas  tar  or  coke-oven  tar;  it  shall  be  completely  liquid  at  thirty- 
eight  (38)  degrees  Centigrade  and  shall  be  free  from  suspended  matter; 
the  specific  gravity  of  the  oil  at  thirty-eight  (38)  degrees  Centigrade 
shall  be  at  least  1.025.  When  distilled  by  the  common  method — that  is, 
using  an  eight  (8)  ounce  retort,  asbestos-covered,  with  standard  ther- 
mometer, bulb  one-half  (^)  inch  above  the  surface  of  the  oil — the  creosote, 
calculated  on  the  basis  of  the  dry  oil,  shall  give  not  more  than  ten  (10) 
per  cent,  distillate  below  two  hundred  and  ten  (210)  degrees  Centigrade, 
not  more  than  forty  (40)  per  cent,  below  two  hundred  and  thirty-five 
(235)  degrees  Centigrade;  and  the  residue  above  three  hundred  and  fifty- 
five  (355)  degrees  Centigrade,  if  it  exceeds  five  (5)  per  cent,  in  quantity, 
shall  be  soft.  The  oil  shall  not  contain  more  than  three  (3)  per  cent,  water. 

The  specification  of  the  American  Telephone  and  Telegraph  Company1 
is  as  follows : 

General. — The  material  desired  under  these  specifications  is  that 
known  as  dead  oil  of  coal-tar,  or  coal-tar  creosote,  obtained  through  the 
distillation  of  gas  tar  produced  by  the  destructive  distillation  of  bitu- 
minous coal,  either  in  the  manufacture  of  coal  gas,  or  in  the  manufacture 
of  coke  by  the  by-product  process.  It  shall  be  without  adulteration. 
Information  shall  be  furnished  on  request  as  to  the  origin  of  the  oil  and 
the  names  of  the  parties  through  whose  hands  it  may  have  passed.  A 
copy  of  any  analysis  of  the  oil  that  may  have  been  made  prior  to  its  use 
shall  also  be  furnished.  The  right  is  reserved  to  take  representative 
samples  of  the  oil  and  test  the  same  wherever  desired. 

Requirements. — All  dead  oil  of  coal-tar  furnished  under  these  speci- 
fications shall  conform  to  the  following  requirements : 

First. — The  oil  shall  have  a  specific  gravity  of  at  least  one  and  three 
one-hundredths  (1.03)  at  thirty-eight  degrees  Centigrade  (38°C.). 

Second. — The  oil  shall  be  thoroughly  liquid  at  a  temperature  of  thirty- 
eight  degrees  Centigrade  (38°C.). 

Third. — When  one  hundred  grams  of  the  oil  are  distilled  in  accordance 
with  the  requirements  of  the  specifications  for  the  analysis  of  dead  oil 
of  coal-tar  or  coal-tar  creosote  hereinafter  referred  to — 

(a)  Not  more  than  five  (5)  per  cent,  shall  distil  off  up  to  205°C. 

(b)  Not  more  than  thirty-five  (35)  per  cent,  shall  distil  off  up  to  235°C. 

(c)  The  fraction  coming  over  between  210°C.  and  235°C.  shall  solidify 
on  cooling  to  20°C. 

(d)  -Not  more  than  eighty  (80)  per  cent,  shall  distil  off  up  to  315°C. 

1  Specification  No.  3,340,  dated  March  11,  1911  (in  force  April,  1912). 


PRESERVATIVES  APPLIED  WITHIN  WOODS 


347 


(e)  The  oil  shall  not  contain  more  than1  two  (2)  per  cent,  of  water. 

(/)  The  quantity  of  tar  acids  present  in  the  fractions  distilling  below 
300°C.  shall  not  exceed  eight  (8)  per  cent,  (measured  by  volume)  of  the 
total  sample  distilled. 

(gr)  The  sulphonation  residue  from  the  fraction  distilling  between 
300°C.  and  360°C.  shall  not  exceed  twenty-five  one  hundredths  (0.25) 
cubic  centimeters. 

Fourth. — The  oil  shall  be  free  from  acetic  acid  and  acetates. 

Fifth. — The  constituents  of  the  oil  insoluble  in  benzol  shall  not  exceed 
one  (1.0)  per  cent,  by  weight. 


Thermometer 


Sheet  Asbestos  should 
rest  against  Glass  Neck 
must  never  Touch  Cork 
Stopper 


Retort 


Asbestos 
Sheet 


Wire  Gauze 


Bunseu  Burner 


FIG.  74. — Apparatus  for  analysis  of  creosote  used  by  American  Telephone 

and  Telegraph  Co. 

Analysis. — The  oil  shall  be  analyzed  in  accordance  with  the  methods 
outlined  in  the  Specifications  for  the  Analysis  of  Dead  Oil  of  Coal-tar 
or  Coal-tar  Creosote. 


1  NOTE. — When  unseasoned  timber  is  being  treated  for  the  Telephone 
Company  by  the  cylinder  pressure  process,  using  steam  for  seasoning,  the 
oil  may  contain  not  more  than  five  (5)  per  cent,  of  water.  But  in  case 
more  than  two  (2)  per  cent,  of  water  is  present  in  the  oil,  the  quantity  of 
the  preservative  added  to  the  timber  shall  be  increased  by  an  amount 
sufficient  to  ensure  that  the  required  amount  of  oil  computed  on  a  water- 
free  basis  has  been  taken  up  by  the  timber. 


348  ORGANIC  STRUCTURAL  MATERIALS 

The  United  States  Forest  Service  Specification  for  Creosote 
gives  much  attention  to  methods  of  analysis.1 

Specifications  for  Analysis  of  Creosote. — The  importance  of 
details  in  analyzing  creosotes  has  been  mentioned.  The  methods 
and  devices  employed  in  determining  the  proportions  of  creosote 
separated  between  certain  temperatures,  the  methods  of  measur- 
ing viscosity,  and  those  employed  to  determine  other  properties, 
influence  the  results  obtained.  This  is  partly  shown  in  the  quo- 
tation that  follows:2 

"The  most  important  part  of  a  creosote  analysis  is  the  fractional 
distillation,  since  by  this  operation  an  approximate  determination  is 
made  of  the  relative  proportions  of  the  most  important  substances  in 
tar  oil.  There  has  been  considerable  divergence  of  opinion  as  to  the 
best  way  of  carrying  out  the  fractionation  of  tar  oils,  some  recommend- 
ing a  retort  as  a  distilling  vessel  and  certain  temperatures  for  taking 
fractions,  others  recommending  a  distilling  flask  and  a  different  set  of 
temperatures." 

The  shape  of  the  distilling  vessel  is  important,  since  it  exerts 
an  influence  upon  the  quantities  and  the  constituents  of  the 
parts,  or  fractions  that  are  distilled.  It  is  also  necessary  to 
decide  upon  the  limits  of  temperature  and  the  number  of  these 
limits  that  are  to  isolate,  or  divide  the  parts  or  fractions. 

The  forms  that  follow  show  methods  of  reporting  analyses. 
The  first  and  second  forms  have  been  used  to  report  the  results  of 
analyses  in  which  the  oil  was  divided  into  ten  and  eleven  frac- 
tions, while  the  last  form  was  used  to  report  an  oil  that  ran  high 
in  naphthalene. 


l"  Standard  Method  for  Analysis  of  Coal-tar  Creosote,"  von  Schrenk, 
Fulks,  and  Kammerer  (American  Railway  Engineering  Association,  Bulletin 
No.  65).  See  also  American  Railway  Engineering  Association  Manual, 
1911,  p.  441.  "The  Fractional  Distillation  of  Coal-tar  Creosote,"  Dean  and 
Bateman  (United  States  Forest  Service,  Circular  No.  80). 

2  United  States  Forest  Service,  Trade  Bulletin  No.  13;  other  references  are 
United  States  Forest  Service  Circular  No.  80;  American  Railway  Engineer- 
ing Association  Bulletins  No.  65  and  No.  72;  Specifications  of  the  American 
Telephone  and  Telegraph  Company,  New  York  Telephone  Company;  also 
sources  enumerated  in  preceding  footnote. 


PRESERVATIVES  APPLIED  WITHIN  WOODS 
ANALYSIS  OF  DEAD  OIL  OF  COAL  TAR 


349 


Sample  No.  1 
Manufactured  by : 
Purchased  from : 


Date: 


191  . 


SUMMARY  OF  RESULTS 


Specific  Gravity  at  38°C. : 
Condition  at  38°C. : 


FRACTIONATION 


Weight  of  retort 

Weight  of  retort  and  oil 

Fraction 
number 

Temperature 

Per  cent. 

Weight  of 
vessel 

Weight  of 
vessel  and 
contents 

Weight 
of 
contents 

! 

1 

170°C. 

2 

170°C.  to  205°C. 

3 

205°C.  to  210°C  . 

4 

210°C.  to  235°C. 

5 

235°C.  to  245°C. 

6 

245°C.  to  270°C. 

7 

270°C.  to  300°C. 

8 

300°C.  to  315°C. 

9 

315°C.  to  360°C. 

10 

Residue  (in  retort) 

Total  per  cents,  found: 

Loss  per  cent. : 

Oil  distilling  below  205°C. : 

Oil  distilling  below  235°C. : 

Oil  not  distilling  below  315°C: 

Water: 

Sulphonation  residue: 

Tar  acids : 

Insoluble  in  benzol : 

Acetic  acid  or  acetates : 

Condition  of  naphthalene  fraction  (210°-235°)  when  cooled  to  20°C. 


Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Cubic  centimeters 

Cubic  centimeters 

Per  cent. 


350 
No.  2 


ORGANIC  STRUCTURAL  MATERIALS 


Creosote 


. — DISTILLATION  No.  23 

50  Date  3/  I/  17 


Analyst 


No. 

Temp. 

Flask 

Flask 

Dist. 

Per  cent. 

Character 

1 

170 

49.53 

47.34 

2.19 

0.876 

1.  Water  —  some  naph. 

2 

170-205 

47.11 

45.49 

1.62 

0.648 

2.  Light  oil  —  some  naph. 

3 

205-210 

42.80 

40.77 

2.03 

0.812 

3.  Light  oil  —  some  naph. 

4 

210-235 

86.45 

51.97 

34.48 

13.792 

4.  Nearly  solid. 

5 

235-245 

71.44 

46.34 

25.10 

10.040 

5.  Solid. 

6 

245-255 

68.80 

49.18 

19.62 

7.848 

6.  Semi-solid. 

7 

255-270 

70.90 

48.78 

22.12 

8.848 

7.  Very  thin  paste. 

8 

270-285 

60.40 

44.73 

15.67 

6.268 

8.  Very  thin  paste. 

9 

285-300 

59.59 

41.02 

18.57 

7.428 

9.  Thin  paste. 

10 

300-320 

80.82 

52.38 

28.44 

11.370 

10.  Thick  paste. 

11 

320-350 

98.32 

50.37 

47.95 

17.180 

11.  Solid. 

Res 

idue  

128.55 

97.32 

31.23 

12.492 

Remarks:  Oil  almost  liquid 

99.608 

No.  3.  REPORT  OF  TEST  OF  COAL-TAB  CREOSOTE 

Date:  July  10,  1917.  Analyst 

Sample  from  overflow  pipe.  Temperature,  48°C. 

Oil  supplied  by—  Boiling,  210°C. 

Specific  gravity,  1 . 021.  Melting  point,  46°C. 

Weight  Retort  104.71  gr. 

Retort  and  Contents,  204.47  gr.   Contents,  99.76  gr. 
Retort  and  Residue,  120 . 73    Residue,  16 . 02  gr. 

DISTILLATION 


Temp. 

Fraction 

Tube 

Weight  of 
tube  and 
contents 

Con- 
tents 

Per  cent, 
ol 
whole 

-170° 
170°-205° 
205°-210° 
210°-235° 
235°-240° 
240°-270° 
270°-316° 

Phenols,hydrocarbonsand  water 
Phenols  and  cresols  

22.44 
18.89 
20.25 
20.90 
12.91 
19.85 
17.44 

22.33 
22.39 
27.43 
67.75 
18.50 
31.01 
26.37 

0.09 
3.50 
7.18 
46.85 
5.59 
11.16 
8.93 

0.09 
3.50 

7.20 
46.94 
5.60 
11.19 
8.95 
16.06 
0.47 

Phenols  and  naphthalene  .... 

Naphthalene  .   ... 

Naphthalene  and  anthracene  oil 
Anthracene  oil  

Anthracene  

Residue 

Loss 

Total      

100.00 

Time :     (    40°  to  210° 29  min.      235°  to  270° 27  min. 

\  210°  to  235° 21  min.      270°  to  316° 29  min. 

•Percentage  of  naphthalene  53.34  per  cent,  (obtained  by  adding  half  of  the 
percentage  of  the  phenols  and  naphthalene,  and  naphthalene  and  anthracene 
oil  fractions  to  the  percentage  of  the  naphthalene  fraction). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  351 

Required  Quantities  of  Creosote. — These  depend  upon  the 
way  in  which  the  wood  is  used.  For  example,  large  quantities 
of  creosote  cannot  be  used  in  paving  blocks  because  of  the  possi- 
bility that  such  blocks  will  annoy  pedestrians  by  "bleeding"  or 
giving  up  creosote  when  exposed  to  the  sun.  On  the  other  hand, 
timbers  that  are  to  be  submerged  in  marine  positions  require 
considerable  quantities  of  creosote. 

Practices  differ  with  localities,  woods,  and  the  uses  for  which 
the  woods  are  intended.  In  the  United  States,  railway  ties  are 
sometimes  treated  with  quantities  as  small  as  six  or  eight  pounds 
to  the  cubic  foot,  although  the  usual  local  practice  is  to  treat 
them  with  ten  or  more  pounds  to  the  cubic  foot.  Depending 
upon  a  wide  range  of  conditions,  piles  are  usually  made  to  receive 
from  twelve  to  twenty-four  pounds  to  the  cubic  foot. 

An  eastern  wood  preserver  advises  as  follows : 

"In  this  section  of  the  country  (New  York)  it  is  customary  to  subject 
a  railroad  tie  to  a  treatment  of  eight  to  twelve  pounds  of  creosote  per 
cubic  foot  of  wood.  If  we  figure  that  a  standard  tie  of  seven  inches  by 
nine  inches  by  eight  feet  six  inches  is  being  used,  this  would  make  a  total 
injection  of  thirty  to  forty-four  pounds  of  creosote  oil  into  each  tie, 
depending  upon  the  treatment  used.  The  treatment,  of  course,  depends 
upon  the  conditions  under  which  the  tie  is  to  be  used,  whether  the  con- 
ditions are  severe  or  mild." 

"In  northern  waters,  twelve  to  sixteen  pounds  of  creosote  oil  per  cubic 
foot  of  wood  is  considered  sufficient  for  the  protection  of  the  piling. 
However,  in  the  south,  where  the  piling  is  subject  to  the  ravages  of  the 
teredo,  etc.,  it  is  considered  good  practice  to  creosote  the  piling  to  point 
of  refusal,  which  is  from  twenty  to  twenty-four  pounds  per  cubic  foot." 

It  should  be  remembered  that  some  engineers  believe  that  much 
of  the  value  of  creosote  depends  upon  the  fact  that  it  keeps  wood- 
fiber  dry,  and,  therefore,  think  that  it  should  be  used  in  compara- 
tively large  quantities,  as  in  the  so-called  " full-cell"  processes;- 
while  others  regard  its  antiseptic  value  more  exclusively,  and, 
in  ties,  use  smaller  quantities,  as  in  the  " empty-cell"  processes. 

Distribution  of  Creosote. — Experience  has  shown  that  the 
distribution  of  creosote  throughout  every  part  of  every  piece  is 
impracticable  and  unnecessary,  but  that  the  thorough  penetra- 
tion into  the  sapwood  and  outer  parts  is  of  vital  importance.  It 
is  fortunate  that  sapwood,  because  of  its  comparative  porosity, 
and  because  of  its  position  upon  the  outside  of  the  timber,  receives 
creosote  so  much  more  easily  than  heartwood  receives  it. 


352  ORGANIC  STRUCTURAL  MATERIALS 

The  tendency  of  preservatives  to  lodge  near  surfaces  indicates 
the  desirability  of  framing  timbers  before  they  are  treated. 
Europeans  bore  ties  before  they  are  treated,  and  finally  insert- 
wooden  dowels  into  the  borings;  these  dowels,  and  not  the  ties, 
receive  the  spikes. 

MISCELLANEOUS  MATERIALS.— Several  proprietary  wood- 
preserving  compounds  are  in  existence;  these,  although  recom- 
mended for  ties,  are  principally  used  for  small  pieces,  or  for  fresh 
exposures  where  timbers  are  cut  and  framed  upon  the  ground. 
Carbolineum,  woodiline,  spiritine,  and  others  are  of  this  group. 

Carbolineum. — The  base  of  this  mixture  is  understood  to  be 
a  modified  coal-tar  creosote  that  differs  from  ordinary  creosote  in 
that  the  lower  distilling  fractions  have  been  largely  removed. 
Several  compounds  are  sold  under  the  name  "  Carbolineum."1 

Avenarius  Carbolineum. — This  mixture,  invented  by  Avenar- 
ius  in  Germany,  in  1869,  has  been  upon  the  market  since  1876. 
An  analysis  furnished  by  the  manufacturer,  published  by  Filsinger 
in  the  "Chemicker  Zeitung"  of  April  18,  1891,  and  referred  to  in 
Lunge's  " Coal-tar  and  Ammonia,"  is  as  follows: 

ANALYSIS 

Color Red  brown. 

Specific  Gravity  at  62  degrees  F 1 . 128 

Viscosity  at  62  degrees  F.  (water  1) 10.00. 

Mineral  matter 0. 03  per  cent. 

Flashing  point 270  degrees  F. 

Burning  point 370  degrees  F. 

Begins  to  distil  at 445  degrees  F. 

Distils  from  445  degrees  to  520  degrees  F 10. 6  Vol.  per  cent. 

Distils  from  520  degrees  to  570  degrees  F 12.0  Vol.  per  cent. 

Naphthalene  (at  410  degrees  to  446  degrees  F.) No  separation. 

Phenols  (carbolic  acid  aac.  Seubert) 0.00  per  cent. 

Residue a  clear  red-brown  thick  fluid. 

Avenarius  Carbolineum  is  described  by  the  manufacturers  as 
follows  :2 

"To  give  a  short  definition  for  Avenarius  Carbolineum,  we  would 
say  that  it  is  a  liquid  oil  from  the  very  highest  boiling  and  least  volatile 
fractions  distilled  from  coal-tar.  It  is  of  course  a  mixture  of  oils  and 


1  The  name  "Carbolineum"  was  registered  by  Richard  Avenarius  at  the 
Patent  Office  in  Washington,  see  No.  14,048.     The  American  Telephone  & 
Telegraph   Company   purchase    "Carbolineum"   under   the   specifications 
included  in  the  Appendix. 

2  Correspondence,  February  24,  1912,  quoted  by  permission. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  353 

not  a  single  substance,  but  this  mixture  is  rigidly  controlled  and  the 
composition  of  this  product  held  is  more  constant  than  any  other  oily 
wood  preservative,  insuring  uniformity  of  composition  and  certainty  of 
action." 

PROCESSES  USED  TO  INTRODUCE  PRESERVATIVES  WITHIN 

WOODS 

The  process  is  quite  as  important  as  the  material.  The  im- 
pregnation must  be  deep  and  well  distributed  through  the  outer 
parts  of  the  pieces,  and  the  wood  must  not  be  injured  by  the  proc- 
esses used  to  secure  this  impregnation  and  distribution.  Within 
limits,  the  same  process  may  be  used  to  introduce  any  preserva- 
tive through  any  species  of  wood,  but,  in  practice,  certain  proc- 
esses have  become  more  or  less  associated  with  certain  preserva- 
tives. The  process  may  be  considered  as  it  includes  (1)  the 
preparation,  and  (2)  the  impregnation  of  the  wood. 

Europeans  once  prepared  practically  all  woods  that  were  to 
receive  preservatives  by  first  steaming  them.  But,  at  the  pres- 
ent time,  much  of  the  best  European  practice  excludes  the 
application  of  steam  save  to  woods  that  are  to  receive  watery 
solutions.  The  woods  that  are  to  receive  creosotes  are  usually 
prepared  by  drying.  In  the  United  States,  early  practices 
included  preparatory  steaming,  and  it  is  yet  thought  to  be  better 
to  steam  the  imperfectly  seasoned  woods  that  are  presented  in 
such  quantities  for  treatment  in  the  United  States,  than  to  hold 
them  in  the  yard  until  they  are  dry. 

The  second  part  of  the  preservative  process,  that  is,  the  part 
during  which  woods  prepared  by  drying  or  by  steaming  are 
brought  into  contact  with  the  preservative,  may  be  carried  out  in 
many  ways :  woods  may  be  dipped  into  or  soaked  in  the  preserva- 
tive, or  the  preservative  may  be  applied  with  a  brush,  or  may  be 
forced  into  the  wood  by  pressure  applied  within  a  cylinder. 

Regardless  of  details,  all  methods  employed  to  introduce  chem- 
ical compounds  within  woods  may  be  grouped  as  they  are  (1) 
Superficial  Processes,  (2)  Non-pressure  Processes,  and  (3)  Pres- 
sure Processes. 

SUPERFICIAL  PROCESSES 

Many  attempts  have  been  made  to  introduce  preservatives  into 
woods  without  the  assistance  of  pressure,  and  several  of  these 
attempts  have  yielded  more  or  less  final  and  satisfactory  results. 


354 


ORGANIC  STRUCTURAL  MATERIALS 


DIPPING,     SOAKING,    BRUSH    APPLICATIONS.— These 

methods  are  often  applied  to  small  pieces  such  as  shingles  and 
fence  posts,  and  sometimes  to  larger  pieces  such  as  telegraph 
poles;  but,  in  the  latter  case,  they  are  normally  considered  where 
treatment  is  to  be  confined  to<certain  parts  of  the  timber.  As  for 
example,  in  the  case  of  telegraph  poles  it  is  usually  best  to  treat 
only  those  portions  that  are  to  extend  into  the  ground. 

Dipping  and  soaking  include  longer  or  shorter  immersions  in 
the  preservative.     Both  practices  are  economical  as  to  labor,  while 


FIG.  75. — Treating  poles  by  brush  method.1 

the  latter  has  the  advantage  of  giving  the  preservative  a  better 
opportunity  to  penetrate  cracks  and  other  places  that  cannot  ordi- 
narily be  reached  by  brushes.  When  soaking  is  practised,  the  wood 
should  remain  in  the  preservative  for  at  least  fifteen  or  twenty 
minutes.  Dipping  should  be  repeated  several  times.  The  results 
from  both  processes  are  better  when  the  preservative  is  heated. 

1  Acknowledgment  to  United  States  Department  of  Agriculture. 


REFERENCES. — "Prolonging  the  Life  of  Telephone  Poles,"  Grinnell 
(United  States  Department  of  Agriculture,  Year  Book,  1905);  "Brush  and 
Tank  Pole  Treatments,"  Crawford  (United  States  Forest  Service,  Circular 
No.  104);  "Wood  Preservation  in  the  United  States,"  Sherfesee  (United 
States  Forest  Service,  Bulletin  No.  78);  "Preservative  Treatment  of  Poles," 
Kempfer  (United  States  Forest  Service,  Bulletin  No.  84);  etc.,  etc. 


PLATE  XVI.    TROUGH  EMPLOYED  IN  KYAN  PROCESS 


PRESERVATIVES  APPLIED  WITHIN  WOODS  355 

Brush  applications  cost  more  for  labor  than  do  dipping  and 
soaking,  but  the  large  receptacles  necessary  for  dipping  and  soak- 
ing are  not  required  when  preservatives  are  applied  with  brushes. 
In  the  latter  case  the  warm  preservative  is  brushed  on  much  as 
paint  is  applied.  The  wood  should  receive  at  least  two  coats. 
The  penetration  is  superficial,  but  the  fact  that  the  piece  is  sur- 
rounded by  what  is  really  a  thin,  antiseptic  "  case"  is  of  assistance 
as  long  as  the  case  can  be  preserved. 

NON-PRESSURE  PROCESSES 

THE  KYAN  PROCESS.—  This  was  probably  the  first  wood- 
preserving  process  used  in  the  United  States,  and  it  is  yet  among 
the  best.  But  its  usefulness  is  limited,  because  the  preservative 
employed  is  so  expensive. 

The  timbers  are  placed  in  open  non-metallic  troughs  filled 
with  mercury  bichloride  solution  and  are  held  below  the  surface 
of  the  solution  by  heavy  weights  such  as  large  stones.  The  sub- 
mergence thus  obtained  is  continued  for  periods  that  depend 
upon  the  shapes  and  sizes  of  the  timbers  treated.  Besides  the 
trough,  there  are  facilities  for  mixing  and  storing  the  solutions, 
but  the  entire  plant  is  simple  and  very  cheap.  It  is  compara- 
tively easy  to  obtain  good  results  from  the  Kyan  process  in  almost 
any  locality.  An  ordinary  oil  cask  is  enough  to  hold  several 
fence  posts  with  sufficient  solution  to  influence  the  portions  with 
which  the  solution  comes  into  contact. 

It  will  be  remembered  that  mercury  bichloride  dissolves  in  very 
hot  water,  and  that  the  strength  of  the  solution,  which  diminishes 
as  wood  is  soaked  in  it,  must  be  brought  back  to  the  required  limit 
whenever  necessary.  It  will  also  be  remembered  that  mercury 
bichloride  is  poisonous  to  human  beings,2  and  that  it  attacks  iron. 
The  Kyan  method,  which  requires  less  expert  care  than  any  other, 
was  suggested  in  1832  by  an  Englishman  named  Kyan. 

THE  OPEN-TANK  PROCESS.—  Many  attempts  have  been 
made  to  perfect  this  process  which  is  designed  to  treat  susceptible 
timbers  without  the  aid  of  cylinders.  The  apparatus  required  is 
comparatively  simple  and  the  results  obtained  are  more  or  less 


Prolonging  the  Life  of  Telephone  Poles,"  Grinnell  (Yearbook 
of  Department  of  Agriculture,  1905). 

2  If  this  poison  is  taken  into  the  stomach  the  patient  should  receive 
quantities  of  fresh  milk,  or  egg  water,  made  by  dissolving  three  or  four  eggs 
in  one  quart  of  water. 


356 


ORGANIC  STRUCTURAL  MATERIALS 


satisfactory.  The  open-tank  process  is  particularly  convenient 
when  small  quantities  of  impressionable  woods  are  to  be  treated, 
or  where  the  treatment  is  to  be  localized  as  at  the  ends  of  posts  or 

poles.  It  has  not  yet  been  widely 
adopted,  however,  nor  is  it  likely 
that  it  will  ever  be  extensively  em- 
ployed by  those  who  treat  the 
largest  quantities  of  woods. 

The  timbers  placed  in  an  open 
reservoir  are  treated  with  hot,  and 
then  with  cool  baths  of  the  anti- 
septic solution.  The  changes  of 
temperature  may  be  obtained  as 
follows :  first,  after  the  pieces  have 
remained  in  the  hot  preservative 
for  a  sufficient  time  the  fire  may 
be  withdrawn  and  the  preservative 
allowed  to  cool;  or  second,  the 
pieces  to  be  treated  may  be  trans- 
ferred from  a  tank  containing  hot 
preservative  to  another  tank  con- 
taining cool  preservative;  or  again 
after  the  pieces  have  remained  for 
a  sufficient  time  in  the  hot  pre- 
servative the  latter  is  replaced  by 
the  cooler  liquid. 

The  time  required  for  penetration 
varies  with  seasoning,  species,  and 
other  factors ,  and  in  every  instance, 
must  be  determined  by  actual  test. 
It  should  be  noted  that  sufficient 

penetration  cannot  be  obtained  from 
FIG.  76.— Open-tank  for  Butt  - 

treatment  of  long  poles.  From  REFERENCES. — "Prolonging  the  Life 
''Preservative  Treatment  of  of  Telephone  Poles,"  Grinnell  (United 
Poles.  Kempfer  (United  States  -.  _f  c  A  .  ,,  v 

Forest  Service,  Bulletin  No.  84).  States  Department  of  Agriculture,  Year 

Book,  1905);   "The  Open-tank  Method 

for  the  Treatment  of  Timber,"  Crawford  (United  States  Forest  Service, 
Circular  No.  101,  1907);  "Brush  and  Tank-pole  Treatments,"  Crawford 
(United  States  Forest  Service,  Circular  No.  104,  1907);  "Wood  Preserva- 
tion in  the  United  States,"  Sherfesee  (United  States  Forest  Service, 
Bulletin  No.  78,  1909);  "Preservative  Treatment  of  Poles,"  Kempfer 
(United  States  Forest  Service,  Bulletin  No.  84,  1911);  "Preservation 
of  Structural  Timber,"  Weiss  (1915);  etc.,  etc. 


PRESERVATIVES  APPLIED  WITHIN  WOODS 


357 


a  hot  solution  only.  On  the  contrary,  the  absorption  usually  takes 
place  during  that  part  of  the  process  where  the  oil  is  cool.  The  prin- 
cipal function  of  the  hot  bath  seems  to  be  to  prepare  the  wood  for  treat- 
ment. A  general  case  would  be  as  follows:  The  preservative  solution 
is  heated  to  from  190  degrees  to  210  degrees  Fahrenheit.  Timbers  are 
then  placed  in  the  warm  solution  in  which  they  are  permitted  to  re- 
main for  from  two  to  six  hours,  after  which  they  are  placed  in  the  cool 
solution  in  which  they  remain  for  from  two  to  twelve  hours. 

The  tanks  employed  in  experiments  upon  large  poles  have  been  of 
two  kinds.  In  some,  the  bottoms  are  inclined  so  that  poles  can  be 
placed  in  and  withdrawn  from  the  tanks  without  the  aid  of  derricks  or 
other  machinery.  This  form  is  convenient,  but  does  not  represent  an 
economical  design  for  permanent  installation,  because  the  large  surface 
of  oil  favors  the  evaporation  of  the  preservative,  and  because  only  a 
few  poles  can  be  treated  at  the  same  time. 


FIG.  77. — Simple  apparatus  for  treating  posts.1 

Other  designs  provide  cylindrical  or  rectangular  treating  tanks,  in 
which  the  poles  are  placed  vertically.  Such  tanks  restrict  the  surface 
of  the  preservative  exposed  to  the  air  and  are  thus  more  economical;  but, 
these  vertical  tanks  require  derricks  for  handling  the  poles,  and  are  usu- 
ally intended  to  be  operated  in  connection  with  the  steam  boilers  em- 

1  From  "Preservative  Treatment  of  Farm  Timbers,"  Willis  (United  States 
Department  of  Agriculture,  Farmers'  Bulletin  No.  387). 


358 


ORGANIC  STRUCTURAL  MATERIALS 


ployed  to  heat  the  preservative.  A  storage  tank,  an  oil  pump,  and  an 
emptying  tank  can  be  added  to  the  equipment  if  the  amount  of  work 
contemplated  and  the  time  required  for  treating  each  charge  are  of  suffi- 
cient importance  to  warrant  their  use. 

The  simplest  kind  of  apparatus  is  sufficient  where  only  a  few  short 
pieces  of  responsive  wood  are  to  be  treated.  That  shown  in  the  lower 
picture  (see  Fig.  77)  is  not  likely  to  be  satisfactory  if  used  many 
times,  because  the  connections  between  the  pipes  and  wooden  barrels 
cannot  be  prevented  from  leaking  ultimately.  A  much  better  arrange- 
ment includes  a  light  iron  tank,  about  the  size  of  an  oil  barrel,  fitted 
with  a  U-connection  of  two-inch  pipe,  which  projects  out  for  a  sufficient 
distance  from  the  side  of  the  tank,  and  to  which  the  heat  is  applied. 
The  first  cost  of  this  device  is  greater  than  the  cost  of  that  shown  in 
the  second  picture  but  it  is  more  economical  if  permanency  is  desired. 

It  will  be  remembered  that  woods  differ  in  receptivity,  and 
that  some  kinds  receive  solutions  much  better  than  others. 
This  is  shown  in  some  results  reported  by  Kempfer,  as  follows:1 


3 

Details  of 

treatmen 

t 

Average 

Averag 

Species 

No. 
poles 

Hot  oil 
hours 

Cool  oil 
hours 

Cold  oil 
hours 

Temp,  hot 
oil 
degrees  F. 

penetra- 
tion 
inches 

absorp- 
tion 
pounds 

Chestnut  

16 

10 

14 

228 

0.30 

20.7 

Chestnut  

8 

8 

14 

223 

0.29 

21.3 

Chestnut  
Chestnut 

24 
24 

6 
4 

14 
14 

225 

225 

0.34 
0  33 

23.6 
20  9 

Chestnut... 

24 

6 

2 

229 

0  34 

21  3 

Chestnut....  
Western  Yellow       ( 

16 
42 

4 
3 

14 

2 

231 
170-200 

0.38 
3.10 

20.6 

81.4 

Pine  \ 

56 

3 

14 

170-200 

3.30 

55.5 

A  specification  prepared  by  The  American  Telephone  and 
Telegraph  Company  to  guide  the  treatment  of  the  butts  of  poles 
by  the  Open-tank  Method  is  as  follows:2 

"Method  of  Treatment. 

"Length  of  Treated  Sections. — The  poles  shall  be  arranged  in  the  tank 
so  that  all  poles  shall  be  covered,  throughout  the  treating  process,  with 
oil  for  a  distance  from  the  butt  end  of  not  less  than  that  given  in  the 
following  table: 

1  Condensed  from  United  States  Forest  Service,  Bulletin  No.  84,  Tables 
Nos.  8  and  18. 

2  Specification  2,977,  March  7,  1907  (in  force  April,  1912). 


PLATE  XVII.    OPEN-TANK  PROCESS  APPLIED  TO  BUTT 
TREATMENT  OF  POLES 


(a)  Tank  with  Horizontal  Bottom — The  Poles  Stand  Vertically — The 
Process  is  Without  Change  of  Oil. 


Injector 


Condensing 
Blow-off  Well 


(6)  Tank  with  Horizontal  Bottom— The  Poles  Stand  Vertically— The 
Process  is  With  Change  of  Oil. 

Acknowledgments  to  American  Telephone  and  Telegraph  Company. 

(Facing  page  358.) 


PRESERVATIVES  APPLIED  WITHIN  WOODS 


359 


Feet 

Feet 

Feet 

Feet 

Feet 

Feet 

Length  of  pole            

25 

30 

35 

40 

45 

50 

Length  of  treated  section  from 
butt  of  pole       

6.0 

6.5 

7.0 

7.0 

7.5 

8.0 

"Hot-oil  Treatment. — The  poles  shall  be  kept  in  the  bath  of  dead  oil 
of  coal-tar  maintained  at  a  temperature  of  not  less  than  212°F.  for  cedar, 
chestnut,  and  partially  seasoned  and  green  loblolly  pine  poles,  or  not 
less  than  200°F.  for  seasoned  loblolly  pine  poles,  and  not  more  than 
230°F.  for  seasoned  poles,  for  at  least  five  hours,  partially  seasoned  poles, 
for  at  least  eight  hours,  and  for  green  poles,  for  at  least  ten  hours. 

"Cool-oil  Treatment. — At  the  completion  of  the  hot-oil  treatment,  a 
sufficient  quantity  of  cool  oil  shall  be  admitted  to  the  treating  tank  to 
lower  the  temperature  of  the  oil  to  at  least  100°F.  The  level  of  the  oil 
in  the  tank  shall  be  maintained  by  means  of  an  overflow  outlet  or  an 
emptying  pipe  controlled  by  a  valve.  Poles  shall  be  kept  in  the  cool 
oil  for  at  least  eight  hours. 

"If  it  is  not  possible  to  lower  the  temperature  of  the  oil  as  above 
described,  the  oil  shall  be  allowed  to  cool  by  atmospheric  exposure.  In 
this  case  the  poles  shall  be  kept  in  the  cooling  oil  until  the  temperature 
of  the  oil  has  dropped  to  at  least  110°F.,  but  in  no  case  for  less  than  ten 
hours. 

"The  treated  section  of  the  pole  shall  not  be  exposed  to  the  air  during 
any  portion  of  the  treating  process. 

"Depth  of  Impregnation. — All  poles  shall  be  treated  so  that  the  oil 
impregnation  shall  extend  through  the  sapwood.  One  pole  in  ten  shall 
be  bored  to  ascertain  the  depth  of  penetration  and  such  borings  shall 
be  made  four  (4)  feet  from  the  butt  end.  The  bore  hole  shall  be  filled 
with  hot  dead  oil  of  coal-tar  immediately  after  the  depth  of  penetration 
has  been  ascertained." 

The  advantages  and  limitations  of  the  open-tank  process  have 
been  summarized  by  Kempfer  as  follows:1 

"The  tests  made  by  the  Forest  Service  indicate  that  the  sapwood  of  a 
great  variety  .of  species,  including  nearly  all  of  our  common  native  woods, 
when  seasoned  can  be  successfully  impregnated  by  the  open-tank  pro- 
cess. The  heartwood  of  many  species  offers  considerable  resistance  to 
impregnation  and  cannot  be  so  well  treated  without  pressure.  However, 
with  the  exception  of  a  few  species  having  an  unusually  narrow  sapwood, 
it  is  believed  that  the  thorough  treatment  of  the  sapwood  portion  of 
round  timber  will  afford  good  protection  to  the  entire  stick.  Since  poles 


1  United  States  Forest  Service,  Bulletin  No.  84,  p.  17. 


360  ORGANIC  STRUCTURAL  MATERIALS 

are  almost  always  used  in  the  round,  the  open-tank  process  is  especially 
well  adapted  to  the  treatment  of  this  class  of  timber.  The  apparatus 
required  is  comparatively  simple  and  inexpensive,  especially  where  but 
few  poles  are  to  be  handled,  and  if  desired  can  be  made  portable. 

The  open-tank  process  is  not  adapted  to  the  treatment  of  woods 
which  are  difficult  to  impregnate,  nor  to  unseasoned  or  partially  seasoned 
wood,  and  as  regards  economy  of  operation,  has  not  justified  itself  in 
plants  designed  for  the  treatment  of  the  entire  pole.  The  large  amount 
of  oil  lost  by  volatilization  from  open  tanks  and  the  difficulty  of  accur- 
ately gauging  and  regulating  the  amount  absorbed  are  other  disadvan- 
tages." 

PRESSURE  PROCESSES 

Pressure  processes  are  usually  employed  when  large  quantities 
of  wood  are  to  be  treated.  Not  only  are  such  processes  conven- 
ient and  economical  when  practised  upon  a  large  scale,  but  the 
results  obtained  from  them  are  commonly  more  complete  and 
satisfactory.  In  practically  all  cases  pressure  is  applied  through 
the  instrumentality  of  cylinders.  An  exception,  the  Boucherie 
process,  which  being  of  historic  interest  is  noted  for  completeness, 
required  pressure  but  did  not  make  use  of  cylinders. 

Use  of  Cylinders. — The  use  of  cylinders  is  not  confined 
to  any  single  process  or  preservative.  The  Bethell,  Burnett, 
Rutgers,  Wellhouse,  and  other  pressure  processes  all  employ 
these  devices.  The  cylinders,  which  are  built  of  steel,  are  from 
five  to  ten  feet  in  diameter,  and  from  one  hundred  to  as  much  as 
one  hundred  and  eighty  or  more  feet  in  length,  while  the  thickness 
of  the  metal  is  such  that  working  pressures  of  from  one  hundred 
and  forty  to  two  hundred  and  twenty-five  pounds  can  be  used 
with  safety.  Special  doors,  pumps,  reservoirs,  thermometers, 
gauges,  and  other  parts  complete  the  equipment. 

Timbers  to  be  treated  in  cylinders  are  arranged  loosely  on 
special  cars  so  that  solutions  with  which  they  will  later  come  into 
contact  may  have  the  freest  possible  access  to  their  surfaces. 
The  charges  are  then  weighed  or  measured,  and  are  rolled  into 
the  cylinders,  the  doors  of  which  are  closed  and  bolted. 

The  manipulations  that  follow  vary  with  process,  preservative, 
peculiarities  of  wood,  and  the  wishes  of  those  in  charge.  In  some 
cases  hot  air,  vacuum,  and  solutions  follow  one  another,  while 
in  others  the  order  is  steam,  vacuum,  and  solutions. 

The  degree  of  impregnation  is  determined  by  gauges  that 
connect  with  and  show  the  level  of  the  solutions  in  the  cylinders. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  361 

A  measured  quantity  of  zinc  chloride  solution  of  known  strength, 
if  that  salt  is  used,  or  of  creosote,  or  other  preservative,  is  passed 
into  the  cylinder  and  held  there  under  pressure  until  the  gauges 
show  that  the  desired  amount  of  preservative  has  been  absorbed. 
The  amount  of  absorption  is  also  occasionally  determined  by 
weighing  the  wood  before  and  after  treatment. 

It  is  necessary  to  consider  the  conditions  of  pressure,  heat,  and 
vacuum  that  exist  during  a  process. 


FIG.  78. — Pressed-steel  car  for  cylinder-treatment  of  ties.1 

Pressure. — Pressure  produced  by  pressure  pumps  is  used  either  before 
the  preservative  has  been  forced  into  the  wood,  or,  later,  as  a  means  of 
forcing  it  into  the  wood.  When  pressure  precedes  saturation  it  is  with 
the  idea  that  the  compressed  air  stored  within  the  wood  will  act  subse- 
quently by  driving  out  most  of  the  free  preservative.  This  detail  is 
practised  in  the  Rtieping  and  other  so-called  " empty-cell"  processes. 
In  the  " full-cell"  processes  the  pressure  is  applied  with  the  preservative. 
It  will  be  remembered  that  dry  heat  and  steam  may  both  be  diffused 
by  air  pressure,  which  may  be  manipulated  so  as  to  assist  in  several 
ways.  Pressures  beyond  one  hundred  and  seventy-five  pounds  to  the 
square  inch  are  seldom  required.  The  distinction  between  full-cell  and 
empty-cell  processes  should  be  noted. 

Heat. — Several  results  may  be  accomplished  by  manipulating  heat  in 
and  out  of  cylinders.  The  heat  may  be  wet  or  dry.  Moist  heat,  that 
is,  steam,  expels  moisture  and  impurities  and  cures  green  woods.  Much 
American  practice  depends  upon  the  assumption  that  woody  cells  receive 
foreign  substances  better  when  they  become  wet  and  distended  by  steam- 

1  Photograph  supplied  by  Allis-Chalmers  Manufacturing  Company,  Inc. 


362  ORGANIC  STRUCTURAL  MATERIALS 

ing,  although,  as  a  matter  of  fact,  experiments  have  shown  that  a  larger 
degree  of  penetrability  is  secured  when  the  wood  is  very  dry.  Long 
steaming  is  usually  unnecessary  and  is  often  injurious.  High  heat, 
whether  wet  or.  dry,  should  be  avoided.  Dry  heat,  as  applied  in  kilns, 
cures  woods  as  well  as  shrinks  them.  When  it  is  applied  in  cylinders 
to  woods  that  are  to  receive  preservative  treatment,  it  acts  by  expelling 
moisture  and  by  warming  the  woods  so  that  they  will  receive  the  pre- 
servative better.  Dry  heat  in  excess  of  212  degrees  F.  expels  some  of 
the  volatile  products  of  the  wood,  which  then  becomes  correspondingly 
weak  and  brittle.  The  equivalent  of  this  in  moist  heat  is  not  known. 
When  heat  is  carried  to  the  point  where  charcoal  is  formed  the  durability 
of  the  wood  is  increased  to  some  extent  because  the  parts  that  are 
charred  are  sterilized.  It  is  needless  to  say  that  charring  is  not  practised 
with  woods  that  are  to  receive  antiseptics. 

Vacuum.  —  When  vacuum  succeeds  steam,  it  acts  by  withdrawing  from 
within  the  cell-structures  of  the  wood  vapors  that  have  been  formed 
there  by  the  steam.  There  is  also  a  surprising  quantity  of  half  coag- 
ulated impurity  that  bears  witness  to  the  necessity  of  some  such  cleans- 
ing process.  The  results  of  vacuum  applied  to  recently  steamed  green 
wood  have  been  described  by  Andrews  as  follows:1  "There  is  at  this 
time  no  appreciable  amount  of  moisture  within  the  cylinder.  The  vac- 
uum pump  has  worked  a  very  few  minutes,  however,  when  the  vapors, 
partly  condensed  in  the  pump,  begin  to  pour  from  the  nose  of  the  pump, 
and  they  continue  to  come  for  hours,  filling,  if  the  wood  is  green,  many 
barrels  with  sap." 

The  so-called  "full-cell"  and  "empty-cell"  processes  should  be  dis- 
tinguished from  one  another.  A  full-cell  creosote  process  is  based 
upon  the  assumption  that,  besides  acting  as  an  antiseptic,  creo- 
sote coats  or  fills  the  woody  cells  and  keeps  them  dry;  a  relatively 
large  amount  of  oil  is  here  required.  An  empty-cell  creosote  proc- 
ess is  based  upon  the  assumption  that  the  creosote  acts  princi- 
pally as  an  antiseptic,  and  that  more  or  less  prolonged  contact 
with  it  is  sufficient;  in  this  case  much  of  the  creosote  forced  into 
the  wood  is  withdrawn  and  saved  so  that  this  process  is  less 
expensive. 

These  terms  are  also  used  where  other  preservatives,  besides 
creosote,  are  employed.  General  definitions  would  b6  as  follows  : 

A  full-cell  process  is  one  which  fills  the  walls  and  the  cavities 
of  the  wood  cells  with  the  preservative.  A  maximum  quantity 
of  the  preservative  is  received  in,  and  is  retained  by,  the  wood. 


Hayford  Process  and  Apparatus  for  Preserving  Timber,"  E.  R. 
Andrews  (Journal  of  the  Franklin  Institute,  February  and  March,  1878). 


PLATE  XVIII.     STEEL  CYLINDERS  DESIGNED  FOR  TREATING 

WOOD 


(Photographs  by  Vulcan  Iron  Works.) 


(Facing  page  362.) 


PRESERVATIVES  APPLIED  WITHIN  WOODS  363 

An  empty-cell  process  is  one  by  which  the  walls  of  the  cells 
of  the  wood  are  treated  with  preservative.  The  cell  cavities 
are  not  left  filled.  The  preservative  is  forced  into  the  wood, 
but  much  of  it  is  then  withdrawn.  The  amount  retained  is 
much  less  than  in  the  case  of  the  full-cell  process. 

THE  FULL-CELL  PROCESSES.  The  Bethell  Process.— The 
Bethell  Process  of  impregnation  has  always  been  associated 
with  the  use  of  creosote.  The  original  patent  taken  out  in 
England  in  1838  did  not  include  the  word  "  creosote,"  but,  in- 
stead, referred  to  a  method  by  which  any  one  of  eighteen  sub- 
stances or  mixtures  might  be  introduced  into  wood.  Creosote 
was  an  ingredient  in  one  of  the  mixtures  mentioned,  and  is  yet 
the  preservative  associated  with  this  process.  A  distinct  feature 
of  the  Bethell  Process  as  first  practised  in  Europe  was  that  the 
woods  to  be  treated  were  not  steamed,  and  this  detail  is  yet  prac- 
tised where  the  process  is  exactly  followed. 

More  or  less  completely  seasoned  woods  are  placed  in  cylinders, 
a  vacuum  is  drawn  by  air  pumps  after  which  warm  creosote  is 
directed  into  the  cylinder  and  held  under  a  pressure  of  from  one 
hundred  to  one  hundred  and  eighty  pounds  until  the  required 
absorption  has  taken  place.  It  is  amusing  to  note  than  an  early 
objection  to  this  process  was  founded  upon  the  fact  that  it  forced 
"too  much  creosote"  into  the  wood. 

The  Bethell  Process  was  not  at  first  accepted  in  the  United 
States  because  it  was  costly,  and  because  it  was  not  designed  to 
treat  unseasoned  woods.  Andrews,  writing  in  1878,  stated  that 
this  "defect"  of  the  Bethell  system  had  always  been  recognized 
in  Europe,  where  ties  and  timbers  intended  for  creosoting  were 
stacked  up  for  nine  to  ten  months  to  season. 

The  Bethell  was  the  original  creosote  process  and  it  is  yet  the 
standard.  The  best  results  have  been  obtained  through  its 
instrumentality.  But  the  fact  that  the  process  as  first  detailed 
abroad  is  suitable  only  for  the  treatment  of  seasoned  woods,  and 
the  further  fact  that  large  amounts  of  oil  are  required,  have  led 
to  some  modifications. 

In  the  United  States  the  principal  demand  is  for  the  treatment 
of  green  or  imperfectly  seasoned  woods  and  with  this  in  mind, 

REFERENCES. — "Antiseptic  Treatment  of  Timber,"  Boulton  (Proceed- 
ings Institution  Civil  Engineers,  London,  1884);  "Preservation  of  Timber," 
Report  of  Committee  (American  Society  of  Civil  Engineers,  1885);  "Pres- 
ervation of  Structural  Timber,"  Weiss  (1915);  etc.,  etc. 


364  ORGANIC  STRUCTURAL  MATERIALS 

in  1872,  Hayford  suggested  that  woods  be  prepared  by  steam 
instead  of  by  drying.  With  the  difference  noted  the  Bethell  and 
Hayford  processes  are  alike.  The  latter  title  is  now  seldom  used, 
while  the  title  "  Bethell  Process  "  has  been  extended  in  the  United 
States  to  include  the  preliminary  steaming  of  green  woods,  as 
well  as  the  preliminary  drying  of  seasoned  woods.1 

The  London,  Brighton  &  South  Coast  Railway  Company 
apply  creosote  under  a  specification  as  follows:2 

"The  sleepers,  when  sufficiently  dry,  are  to  be  placed  in  a  wrought- 
iron  cylinder,  and,  when  closed,  a  vacuum  is  to  be  created  by  air  pumps. 
The  creosote,  at  a  temperature  of  not  less  than  120  degrees  Fahr.,  and 
not  more  than  150  degrees,  is  to  be  allowed  to  enter  the  exhausted  cylin- 
der, and  afterwards  is  maintained  there  by  pumping  at  a  pressure  of 
not  less  than  120  pounds  to  the  square  inch.  The  sleepers  are  to  be  kept 
under  this  pressure  until  each  sleeper  has  absorbed  at  least  three  gallons 
of  creosote  on  the  average,  the  quantity  to  be  ascertained  by  weighing. 
Any  charge  of  sleepers  not  giving  the  average  impregnation  of  at  least 
three  gallons  is  to  be  returned  to  the  cylinder  for  further  treatment." 

The  Eppinger  &  Russell  Company  employ  details  as  follows: 
Wood  is  steamed  at  about  twenty-five  pounds  pressure.  The 
steam  is  succeeded  by  vacuum  of  about  twenty-eight  inches;  the 
oil  is  then  admitted  and  held  under  a  pressure  of  from  fifty  to  two 
hundred  pounds,  as  the  quality  of  the  wood  may  indicate.  Such 
minor  changes  are  made  from  time  to  time  as  appear  to  be  sug- 
gested from  experience.3 

A  specification  prepared  by  the  Southern  Creosoting  Company 
of  Slidell,  Louisiana,  is  as  follows:4 

"Steaming  Process. — The  seasoning  of  the  timber  shall  be  accom- 
plished by  the  direct  application  of  live  steam  admitted  into  the  treating 
cylinders.  The  steam  gauge  pressure  in  the  cylinders  shall  be  regulated 
according  to  the  dimensions  of  the  timber.  During  the  process  of  steam- 
ing the  cylinder  must  be  frequently  drained  by  a  valve  located  at  the 
lowest  possible  point.  The  steaming  must  continue  from  three  to  fif- 
teen hours,  according  to  the  size  of  the  lumber  and  the  quantity  of  oil 
to  be  injected  into  it.  At  the  end  of  the  steaming  period  a  vacuum  shall 
be  created  in  the  cylinder,  the  temperature  being  at  all  times  maintained 


1  "The  Hayford  Process  and  Apparatus  for  Preserving  Timber,"  Andrews 
(Journal  of  the  Franklin  Institute,  February  and  March,  1878). 

2  In  force  February,  1916. 

3  In  force  December,  1915. 

4  In  force  January,  1916. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  365 

above  the  boiling  point.  The  vacuum  must  continue  until  the  gauge 
shows  a  reading  of  from  twenty-two  to  twenty-six  inches,  and  to  be  kept 
at  that  reading  until  no  moisture  comes  from  the  bottom  of  the  cylinder. 

"After  the  material  has  been  thoroughly  seasoned  and  it  has  been 
ascertained  that  no  sap  or  moisture  remains  in  the  cylinder,  the  oil  shall 
be  admitted  at  a  temperature  of  not  less  than  120  degrees  Fahr.,  which 
temperature  shall  be  raised  to  not  less  than  185  degrees  Fahr.  under  a 
pressure  of  not  less  than  125  pounds  per  square  inch.  The  force  pump 
producing  this  pressure  shall  be  kept  in  operation  until  the  established 
system  of  measurement  shows  the  wood  to  have  absorbed  the  desired 
quantity  of  oil. 

"The  pressure  shall  then  be  released  and  the  timber  completely 
treated  shall  be  immediately  removed  from  the  cylinders." 

The  American  Telephone  and  Telegraph  Company  applies 
creosote  to  timber  other  than  Douglas  fir  under  the  very  complete 
specification  that  follows.1  The  specifications  do  not  cover  the 
treatment  of  crossarms: 

''General. — These  specifications  describe  the  processes  to  be  used  in 
impregnating  timber,  except  crossarms,  with  dead  oil  of  coal-tar  and  are 
intended  to  include  all  instructions  necessary  for  the  proper  performance 
of  the  work. 

"  Testing  Facilities. — The  manufacturer  shall  provide  and  install  such 
apparatus  as  is  necessary  to  enable  the  inspector  to  determine  that  the 
requirements  of  these  specifications  are  fulfilled.  It  is  suggested  that 
recording  temperature  and  pressure  instruments  be  provided. 

"  Workmanship. — All  material  shall  be  of  the  best  quality  unless  other- 
wise specified  herein  and  all  workmanship  shall  be  sound  and  reliable  in 
character  and  of  the  best  grade. 

Materials 

"Timber. — The  timber  subjected  to  the  creosoting  treatment  shall 
conform  to  the  requirements  of  the  specifications  and  drawings  furnished 
by  the  telephone  company.  All  timber  shall  be  framed,  shaped,  and 
bored  before  treatment. 

"The  material  in  each  charge  shall  be  in  approximately  the  same  con- 
dition so  far  as  air-seasoning  is  concerned,  and  under  no  circumstances 
shall  green,  partially  seasoned,  or  seasoned  timber  be  treated  together 
in  the  same  charge. 

"Two  kinds  of  timber,  for  example  yellow  pine  and  black  gum,  shall 
not  be  treated  together.  When  the  southern  yellow  pines  are  treated, 
longleaf  and  Cuban  pine  shall  not  be  included  in  charges  with  shortleaf 
and  loblolly  pines. 

1  Specification  3,156,  April  3,  1909  (in  force  April,  1912). 


366 


ORGANIC  STRUCTURAL  MATERIALS 


"Only  one  class  of  material  shall  be  treated  in  any  one  charge,  for 
example,  poles  and  ducts  shall  not  be  treated  together. 

Dead  Oil  of  Coal-tar. — The  dead  oil  of  coal-tar  used  in  impregnating 
the  timber  shall  conform  to  the  requirement  of  the  American  Telephone 
and  Telegraph  Company's  Specifications  for  Dead  Oil  of  Coal-tar  or 
Coal-tar  Creosote.  The  telephone  company  shall  have  the  right  to  take 
samples  of  the  oil  whenever  its  inspector  shall  elect.  The  sample  of  oil 
so  collected  shall  be  tested  wherever  the  telephone  company  shall  elect. 

"Quantity  of  Oil. — All  timber  shall  be  so  impregnated  with  dead  oil 
of  coal-tar  that  the  average  impregnation  of  the  material  in  each  cylinder 
load  shall  not  be  less  than  the  quantity  of  oil  called  for  in  the  specifica- 
tions for  the  material  or  in  the  contract.  The  volume  of  timber  and 
the  quantity  of  oil  absorbed  shall  be  determined  by  the  inspector.  The 
inspector  shall  have  access  to  all  records  of  treatment. 

"  Excess  of  oil  in  one  charge  shall  not  be  offset  against  a  shortage  of 
oil  in  another  charge. 

"The  treating  plant  shall  be  equipped,  to  the  satisfaction  of  the  tele- 
phone company,  so  as  to  allow  a  close  determination  of  the  amount  of 
oil  injected  into  the  timber. 

"The  quantity  of  oil  injected  into  the  timber,  as  determined  by  the 
volume  of  oil  withdrawn  from  the  measuring  tanks,  shall  be  based  on 
the  standard  temperature  of  100°F.,  and  the  quantity  increased  by  an 
amount  equal  to  0.00044  of  the  required  volume  at  100°F.  for  each 
degree  Fahrenheit  of  oil  temperature  above  the  standard  temperature 
of  100°F. 

11  Treatment 

"General. — The  treating  cylinder  shall  not  be  opened  during  the  proc- 
ess of  treatment. 

"Classification. — For  the  treating  process  timber  shall  be  classified  as 
heavy  or  small. 

"Heavy  timber  shall  be  understood  to  include  poles  and  stubs;  small 
timber  shall,  unless  otherwise  specified,  include  all  other  timber,  except 
crossarms,  ordered  by  the  telephone  company. 

"Steaming  and  Heating  Process. — Steam  when  used  shall  be  main- 
tained at  a  uniform  pressure  and  temperature  in  the  treating  cylinder 
as  indicated  in  the  following  table : 


Steam  i 

pressure 

Steam  tempera- 
ture 

Not  less  than 

Not  greater  than 

Not  greater  than 

For  heavy  timber.  

17  pounds 

20  pounds 

259°F. 

For  small  timber.    .    . 

12  pounds 

15  pounds 

250°F. 

PRESERVATIVES  APPLIED  WITHIN  WOODS 


367 


"The  temperature  readings  shall  be  taken  by  means  of  standard  ther- 
mometers placed  in  the  treating  cylinder  so  that  the  bulbs  thereof  are 
within  the  shell. 

"At  the  beginning  of  the  steaming  process  the  exhaust  valve  shall  be 
open  and  shall  not  be  closed  until  a  steady  flow  of  steam  escapes  through 
the  valve.  The  duration  of  the  steaming  process  shall  be  timed  from 
the  closing  of  the  exhaust  valve.  The  exhaust  valve  shall  be  opened 
and  the  condensation  blown  off  at  intervals  during  the  steaming  process. 

"The  duration  of  the  steaming  process  shall  be  as  directed  by  the 
inspector  and  shall  depend  upon  the  condition  and  character  of  the  tim- 
ber, but  shall  in  no  case  be  carried  to  such  an  extent  as  to  injure  the 
timber.  The  timber  shall  not  be  steamed  in  excess  of  the  interval  given 
in  the  following  table: 


Green  or  very 
wet  timber 

Partially 
seasoned 
timber 

Seasoned 
timber 

For  heavy  timber  

8  hours 

5  hours 

0  hours 

For  small  timber 

5  hours 

3  hours 

0  hours 

"Seasoned  timber  shall  not  be  steamed,  but  shall  be  heated  in  the 
treating  cylinder.  The  temperature  within  the  cylinder  shall  be  main- 
tained by  means  of  the  closed  heating  coils  at  a  temperature  of  about 
150°F. 

For  heavy  timber for  at  least  2  hours. 

For  small  timber for  at  least  1  hour. 

"Exhaustion  Process.  Green  and  Partially  Seasoned  Timber. — When 
the  steaming  process  shall  have  been  completed  the  steam  shall  be  blown 
off  and  the  treating  cylinder  exhausted  to  a  vacuum  of  at  least  twenty- 
four  (24)  inches  at  or  near  sea  level,  or  proportionately  less  at  higher 
altitudes.  The  vacuum  shall  be  maintained  at  the  above  minimum  for 
a  period:  for  heavy  timber,  of  not  less  than  2  hours;  for  small  timber, 
of  not  less  than  1  hour;  and  if  necessary  thereafter  until  the  condenser 
discharge  is  clear.  During  the  exhaustion  process  the  temperature 
within  the  treating  cylinder  shall  be  maintained,  by  means  of  saturated 
steam  in  the  closed  heating  coils,  above  that  at  which  water  would  boil 
at  that  degree  of  vacuum. 

"Exhaustion  Process.  Seasoned  Timber. — With  seasoned  timber  it  is 
not  required  that  a  vacuum  shall  be  drawn  after  the  heating  process 
and  before'  the  filling  process,  provided  that  the  specified  amount  of 
dead  oil  of  coal-tar  is  in  the  timber  on  its  removal  from  the  treating 
cylinder. 

"Filling  Process. — After  the  exhaustion  process,  the  cylinder  shall  be 
completely  filled,  as  rapidly  as  possible,  with  dead  oil  of  coal-tar  and 
in  no  case  shall  the  flow  of  oil  into  the  treating  cylinder  be  stopped 


368  ORGANIC  STRUCTURAL  MATERIALS 

before  the  overflow  of  the  cylinder.  Pressure  shall  then  be  applied 
until  the  specified  amount  of  oil  has  been  forced  into  the  timber. 

"The  total  amount  of  oil  forced  into  the  timber  shall  be  determined 
from  the  initial  reading  on  the  measuring  tanks  and  the  readings  on  the 
measuring  tanks  after  the  oil  in  the  cylinder  at  the  conclusion  of  the 
pressure  process,  including  all  drip  from  the  timber,  has  been  returned  to 
the  measuring  tanks. 

"The  oil  at  introduction  into  the  cylinder  shall  have  a  temperature 
of  not  less  than  140°F.  and  not  more  than  175°F.  The  oil  in  the  meas- 
uring tanks  shall  be  maintained  at  a  uniform  temperature  during  the 
filling  process. 

''Subsidiary  Specifications. — The  following  specifications  of  the 
American  Telephone  and  Telegraph  Company  form  a  part  of  these 
specifications : 

"  Specifications  for  Dead  Oil  of  Coal-tar,  or  Coal-tar  Creosote. 

"Specifications  for  Analysis  of  Dead  Oil  of  Coal-tar,  or  Coal-tar 
Creosote." 

The  specification  adopted  by  the  American  Railway  Engineering 
Association  is  given  on  page  448  of  the  1911  Manual  published  by  that 
organization. 

The  Burnett  Process. — This  process,  which  was  patented  by 
Burnett  in  1838,  depends  upon  the  use  of  zinc  chloride.  The 
immediate  value  of  this  salt  as  an  enemy  of  wood-destroying 
fungi  is  about  equal  to  that  of  creosote,  but  because  the  salt 
dissolves  readily  in  water,  the  results  are  not  as  lasting.  Neither 
is  it  known  that  zinc  chloride  repels  the  attacks  of  teredos  and 
other  shipworms. 

The  method  of  impregnation  is  similar  to  that  employed  in  the 
Full-cell  Creosote  Process.  The  wood  is  steamed,  partly  dried  in 
a  vacuum  of  from  twenty  to  twenty-five  inches,  and  then  treated 
with  warm  zinc  chloride  solution  which  is  held  under  pressure 
until  the  required  absorption  has  taken  place.  Here  as  elsewhere, 
results  are  influenced  by  attention  paid  to  details.  The  object  is 
to  transfer  the  required  quantity  of  antiseptic  to  the  interior  of 
the  wood,  and  to  secure  the  greatest  practicable  uniformity  of 
distribution  without  injuring  the  wood. 

REFERENCES. — "The  Artificial  Preservation  of  Railroad  Ties  by  the  Use 
of  Zinc  Chloride,"  Curtis  (Transactions  American  Society  Civil  Engineers, 
Vol.  XLII,  1899);  "Handbook  of  Timber  Preservation,"  Rowe  (Author's 
Edition,  1900);  "On  the  Determination  of  Zinc  in  Treated  Timbers," 
Fulks  (American  Railway  Engineering  Association,  Bulletin  No.  65,  1905); 
"Visual  Method  for  Determining  the  Penetration  of  Inorganic  Salts  in 
Treated  Wood,"  Bateman  (United  States  Forest  Service,  Circular  No. 
190) ;  etc.,  etc. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  369 

The  Burnett  Process  is  essentially  a  tie-preserving  process  and 
is  not  suitable  for  timbers  that  are  to  be  exposed  in  marine 
positions.  It  is  cheaper  than  creosoting,  and  particularly  useful 
with  ties  which  are  to  be  exposed  in  climates  and  surroundings 
that  are  not  too  wet.  Under  such  conditions  the  life  of  the  ties  is 
frequently  doubled.  A  field  of  usefulness  is  with  inferior  woods 
that  must  now,  with  the  scarcity  of  better  kinds,  be  employed. 
It  is  needless  to  urge  that  prevention  of  decay  should  be  adjusted 
as  far  as  possible  to  the  natural  mechanical  life  of  the  tie  and  that 
expensive  treatments  are  not  warranted  with  ties  that  wear  out 
before  they  rot.  The  Burnett  and  Full-cell  Creosote  Processes 
were  compared  by  Chanute  as  follows:1 

"An  average  life  of  ten  to  twelve  years  is  being  obtained  by  the  use 
of  zinc  chloride  in  this  country.  It  would  be  possible  to  obtain  a  life 
of  fifteen  to  thirty  years  by  the  use  of  creosote,  but  it  will  be  seen  from 
the  figures  given2  that  this  would  cost  three  to  four  times  as  much  as 
zinc  chloride. 

"  We  must  be  content,  therefore,  either  to  allow  our  cheap  ties  to  decay 
in  the  good  old  way,  or  to  adopt  for  the  present  some  of  the  cheaper 
and  inferior  methods  which  will  produce  shorter  lives  than  obtained  in 
Europe." 

The  Burnett  method  is  much  used  in  the  United  States  and 
Europe. 

THE  EMPTY-CELL  CREOSOTE  PROCESSES.— The  Riiep- 
ing  and  Lowry  processes  have  for  their  object  the  wide  diffusion 
throughout  the  wood  of  limited  quantities  of  creosote.  In  both 
cases  air-seasoned  wood  is  preferred,  although  in  the  Riieping 
Process  green  woods  can  be  and  frequently  are  treated  after  they 
have  been  prepared  by  steaming  and  vacuum  as  in  the  Hayford 
Process. 

The  Riieping  Process. — This  process  is  characterized  by  the 
use  of  compressed  air,  which  is  admitted  to  the  cylinder  and  held 
there  until  the  fabric  of  the  wood  is  thoroughly  penetrated.  At 

1  "The  Preservation  of  Railway  Ties  in  Europe,"  Chanute  (Transactions 
American  Society  of  Civil  Engineers,  Vol.  XLV,  p.  509). 

2  "The  Artificial  Preservation  of  Railroad  Ties  by  the  Use  of  Zinc  Chlo- 
ride," Curtis  (Transactions  American  Society  of  Civil  Engineers,  Vol.  XLII, 
pp.  288-374). 


370  ORGANIC  STRUCTURAL  MATERIALS 

this  stage  the  wood  is  sometimes  described  as  being  "  filled  with 
compressed  air."  Creosote  is  then  admitted  under  a  slightly 
higher  pressure,  the  air  in  the  cylinder  gradually  escaping.  The 
pressure  is  then  raised  to  about  one  hundred  and  fifty  or  more 
pounds,  at  which  point  it  is  made  to  remain  for  a  sufficient  time. 

Finally,  the  pressure  is  released  when  the  air  which  was  first 
introduced  within  the  wood  expands  and  drives  out  much  creo- 
sote. A  vacuum  which  follows  assists  in  this  result.  Consider- 
able oil  thus  recovered  is  referred  to  as  "kick-back."  The  pene- 
tration obtained  during  the  Rtieping  Process  may  be  as  deep  as 
that  secured  during  the  Bethell  Process,  while  at  the  same  time 
much  less  creosote  is  required.  The  Riieping  Process  is  used 
extensively  in  the  United  States  and  in  Europe. 

The  Riieping  Process  is  detailed  by  a  railway  company1 
located  in  the  southeastern  part  of  the  United  States,  as  follows : 

"Compressed  air  is  pumped  into  the  main  cylinder  which  is  filled 
with  timber,  and  into  the  Riieping  cylinder  which  is  filled  with  creosote. 
This  integral  air  pressure,  which  amounts  to  from  twenty-five  to  seventy- 
five  pounds  per  square  inch,  is  the  means  by  which  the  final  amount  of 
oil  to  be  retained  in  the  wood  is  regulated. 

"The  cylinder  containing  the  timber  and  the  Riieping  cylinder  con- 
taining the  creosote  being  under  the  same  pressure,  the  oil  in  the  Riieping 
cylinder  is  directed  into  the  main  cylinder  without  decreasing  the  pres- 
sure in  the  latter  cylinder.  Additional  pressure,  amounting  to  about 
one  hundred  pounds,  is  now  applied  to  the  contents  of  the  main  or  heat- 
ing cylinder  by  means  of  pressure  pumps.  If  the  initial  pressure  was 
sixty-five  pounds,  the  pressure  would  now  be  about  one  hundred  and 
sixty-five  pounds  to  the  square  inch.  The  amount  of  the  pressure  and 
the  duration  of  the  period  during  which  it  is  applied  are  determined  by 
experience. 

"On  the  completion  of  the  pressure  period  a  valve  is  opened  and  the 
pressure  released.  The  one  hundred  pounds  of  pressure  last  applied  is 
itself  first  released  after  which  the  initial  pressure  escapes.  The  initial 
pressure  coming  from  the  interior  of  the  timber  drives  out  the  loose  creo- 
sote and  leaves  only  the  walls  of  the  cells  coated.  A  vacuum  is  drawn 
and  the  charge  is  released." 

The  Lowry  Process. — This  process  differs  from  that  just 
described  in  that  compressed  air  is  not  employed.  The  wood 
is  first  air-seasoned  and  the  air  present  naturally  in  wood  thus 
dried  is  assumed  to  be  sufficient  to  drive  out  superfluous  creosote 

1  The  Charlotte  Harbor  and  Northern  Railway  Company  at  Hull,  Florida. 


PLATE  XIX.    PLANT  FOR  CREOSOTING  LUMBER 


(Photographs  by  Eppinger  &  Russell  Company.) 


(Facing  page  370.) 


PRESERVATIVES  APPLIED  WITHIN  WOODS  371 

after  the  antiseptic  has  been  introduced  by  methods  similar  to 
those  used  in  the  Riieping  Process.  The  Lowry  Process  also 
aims  to  secure  a  deep  penetration  of  creosote  with  less  oil  than  is 
required  by  the  Bethell  or  Full-cell  Process.  The  Lowry  Process 
is  extensively  used  throughout  the  United  States.1 

THE  ZINC-CREOSOTE  PROCESSES.— The  Rutgers,  Card, 
and  Allardyce  Processes  make  use  of  zinc  chloride  and  creosote. 
The  first-named  antiseptic  is  used  because  it  is  cheap,  and  the 
last  is  used  because,  in  addition  to  its  intrinsic  value,  it  retards 
the  escape  of  the  zinc  chloride.  The  two  preservatives  are  forced 
into  the  wood  while  mixed  together  in  the  form  of  an  emulsion, 
or  they  are  introduced  separately  one  after  the  other. 

In  the  Rutgers  Process,  the  zinc  and  creosote  are  introduced 
while  mixed  together  by  means  that  resemble  those  employed  to 
introduce  pure  creosote  during  the  Bethell  Process.  In  Ger- 
many, where  every  attention  is  paid  to  detail,  the  Rutgers  Pro- 
cess has  caused  pine  ties  to  last  for  from  fifteen  to  eighteen  years. 
The  process  has  been  practised  successfully  for  about  forty  years. 

The  Card  Process  differs  from  the  Rutgers  Process  in  the  means 
used  to  mingle  the  antiseptic  liquids.  These  are  first  mixed 
together  by  forcing  air  through  perforated  pipes  located  at  the 
bottoms  of  the  mixing  tanks;  the  agitation  is  then  continued  by 
means  of  centrifugal  pumps.  Further  details  resemble  those 
followed  in  the  Bethell  Process.  The  best  results  are  obtained 
with  air-seasoned  woods. 

The  Allardyce  Process  is  planned  so  that  the  preservatives  are 
introduced  separately  one  after  the  other.  First,  a  solution  of 
zinc  chloride  is  introduced  into  the  wood  by  an  air  pressure  of 
about  130  pounds  per  square  inch.  The  cylinder  is  then  drained 
and  is  refilled  with  creosote  which  is  finally  subjected  to  a  pres- 
sure of  about  180  pounds  per  square  inch.  The  penetration  of 
creosote  is  not  great  and  the  process  itself  is  not  extensively  used 
at  the  present  time. 

THE  ZINC-TANNIN  PROCESS.— In  the  Wellhouse  Process 
glue  and  tannin  are  used  in  attempts  to  retard  the  escape  of 
zinc  chloride.  Otherwise,  the  Wellhouse  and  Burnett  prac- 
tices resemble  one  another.  Both  depend  upon  the  preservative 
properties  of  zinc  chloride;  but  in  the  Wellhouse  Process  glue  and 
tannin,  acting  upon  one  another,  form  inert  solids  which  obstruct 
the  escape  of  the  soluble  zinc  chloride.  The  Wellhouse  Process  is 

1  "  Preservation  of  Structural  Timber,"  Weiss  (1915,  pp.  59-60). 


372  ORGANIC  STRUCTURAL  MATERIALS 

comparatively  cheap  and  has  succeeded  in  greatly  increasing  the 
length  of  life  of  some  perishable  woods.  On  the  whole,  however, 
the  results  secured  from  this  process  have  not  been  as  satisfactory 
as  were  at  first  hoped  for. 

THE  BOILING  PROCESS. — This  process  is  largely  used  for 
the  treatment  of  Douglas  Fir.  Either  green  or  seasoned  woods 
can  be  treated.  The  Boiling  Process  is  described  by  Sherfesee  as 
follows:1 

"This  process  is  used  principally  on  the  Pacific  Coast,  and  for  Douglas 
Fir,  an  exceedingly  difficult  wood  to  treat.  The  timber,  usually  green, 
is  placed  in  the  treating  cylinder,  which  is  then  filled  with  creosote 
heated  to  a  temperature  slightly  above  the  boiling  point  of  water.  This 
hot  bath  is  continued  for  from  several  hours  to  more  than  two  days,  de- 
pending upon  the  size  and  condition  of  the  timber.  During  the  bath 
much  of  the  water  in  the  sap  is  driven  off,  together  with  the  volatilized 
light  oils.  These  vapors  are  caught  in  a  condenser,  the  water  is  decanted 
off,  and  the  oil  is  run  back  into  the  receiving  tank  to  be  used  over  again. 
Finally,  an  oil  pressure  of  100  to  125  pounds  is  applied,  and,  at  the  same 
time,  the  temperature  of  the  oil  is  allowed  to  fall,  thus  forcing  the  pre- 
servative into  the  timber." 

THE  CREO-RESINATE  PROCESS.— As  first  detailed,  wood 
was  subjected  to  dry  heat,  after  which  a  vacuum  was  drawn. 
Creosote,  resin  and  formaldehyde  were  then  applied  while  mixed 
together.  It  is  said  that  woods  were  hardened  as  well  as  pre- 
served by  this  process,  which  has  been  extensively  employed  in 
the  preparation  of  paving  blocks.2 

The  Boucherie  Process. — Cylinders  were  not  employed  in  this  process. 
The  inventor  first  attempted  to  distribute  preservative  substances 
through  the  wood  of  standing  trees  by  introducing  the  substances  into 
the  sap  of  the  trees,  and  the  process  as  patented  called  for  the  presence 
of  sap  or  other  moisture  within  the  wood  that  was  to  be  treated. 

Several  methods  were  ultimately  suggested  by  Boucherie  for  forcing 
solutions  into  the  woods  after  the  trees  had  been  cut  down.3  In  the 
principal  one,  pressure  was  obtained  by  elevating  the  tank  that  contained 
the  solution.  The  tank  thus  elevated  was  connected  with  a  cap  designed 
to  fit  over  one  end  of  the  timber,  and  the  antiseptic  solution  was  passed 

1  "Wood  Preservation  in  the  United  States"  (United  States  Forest  Ser- 
vice, Bulletin  No.  78,  p.  15). 

2  Transactions  of  the  American  Society  of  Civil  Engineers,  Vol.  XLIV. 

3  "Wood  Preservation,"  Flad   (United  States  Forestry  Bulletin  No.   1, 
p.  69). 


PRESERVATIVES  APPLIED  WITHIN  WOODS  373 

from  the  tank  through  the  timber  until  the  moisture  that  emerged  from 
the  opposite  end  of  the  timber  was  proved  by  tests  to  be  nearly  pure. 

The  introduction  of  better  methods  led  to  the  practical  abandonment 
of  the  Boucherie  Process  even  in  France,  where  it  was  most  practised. 
Criticisms  were  that  the  work  had  to  be  done  in  the  forest,  and  that 
every  stick  of  timber  had  to  be  handled  separately.  This  would  have 
prevented  the  method  from  being  used  upon  a  large  scale,  even  if  the 
results  accomplished  by  it  had  been  more  satisfactory. 

Experiments  made  more  recently  to  determine  whether  zinc  chloride 
solution  and  creosote  could  be  forced  into  single  pieces  of  wood  by  pres- 
sure obtained  by  the  use  of  ordinary  hand  pumps,  yielded  results  that 
were  neither  uniform  nor  satisfactory.1  In  this  case,  a  steel  cap  was 
made  to  fit  over  the  butt  of  the  timber.  The  cap  was  connected  with 
the  pump  and  with  the  reservoir  containing  the  hot  preservative. 

Although  the  Boucherie  process  can  be  used  with  other  antiseptics, 
it  is  generally  associated  with  copper  sulphate. 

SOME  MISCELLANEOUS  PROCESSES. 

Charring. — Charring  is  an  internal  as  well  as  an  external  process. 
Not  only  does  the  shell  of  charcoal  protect  from  bacteria,  but  the  wood 
beneath  is  more  or  less  sterilized.  Charring  is  defective  because  its 
field  of  application  is  limited,  and  because  so  much  of  the  wood  is 
destroyed. 

Vulcanizing. — Destructive  heat  was  not  concentrated  as  in  charring, 
but  less  heat  was  diffused  throughout  the  wood  by  means  of  compressed 
air.  The  result  was  accomplished  by  placing  the  wood  in  cylinders  and 
then  subjecting  it  to  dry  heat  with  pressure.  Chandler  reported  favor- 
ably upon  this  process,  which  is  no  longer  practised  upon  a  large  scale. 
Vulcanized  ties  were  used  for  some  time  on  the  New  York  elevated 
railways. 

The  Bobbins  Process. — This  now  historic  method,  from  which  much 
was  expected,  was  designed  to  use  a  minimum  of  creosote  in  the  form 
of  vapor.  The  high  temperature  necessary  to  volatilize  good  creosote 
injures  wood,  and  the  process,  which  failed  in  practical  tests,  was  long 
since  abandoned.  The  Robbins  Company  was  highly  capitalized.  A 
convention  held  in  ttye  Astor  House  in  New  York  in  1869  was  attended 
by  delegates  from  Maine  to  California  who  referred  to  the  inventor  as 
a  "  great  public  benefactor."  The  expectations  of  those  interested  in 
this  process  were  not  realized. 

The  Seeley  Process. — The  charge  was  placed  in  a  bath  of  hot  creosote 
which  was  then  more  or  less  abruptly  replaced  by  cold  creosote.  It  was 
believed  that  the  heat  volatilized  the  sap  in  the  wood,  and  that  the 

l" Prolonging  the  Life  of  Telephone  Poles,"  Grinnell  (United  States 
Department  of  Agriculture,  Year  Book,  1905). 


374  ORGANIC  STRUCTURAL  MATERIALS 

vacuum  caused  by  the  condensation  of  the  vaporized  sap  when  the  cold 
creosote  was  introduced  would  draw  quantities  of  creosote  into  the  wood. 
The  process  was  conducted  in  closed  cylinders.  It  is  interesting  to  com- 
pare it  with  the  open-tank  process. 

The  Powell  Process. — Timber  is  boiled  in  a  strong  solution  of  sugar. 
It  is  claimed  that  seasoned  woods  are  cured  and  the  toughness  is 
increased. 

The  Thilmany  Process. — An  injection  of  copper  sulphate  was  followed 
by  a  bath  of  chloride  of  barium.  An  interchange  of  the  constituents 
of  these  two  salts,  if  brought  together  in  the  proper  proportions,  left 
the  timber  impregnated  with  chloride  of  copper  and  sulphate  of  barium. 
The  insoluble  sulphate  of  barium  was  relied  upon  to  prevent  the  removal 
of  the  soluble  chloride  of  copper. 

The  Hasselmann  Process. — The  wood  was  boiled  in  a  solution  of  cop- 
per sulphate,  iron  sulphate,  aluminum  sulphate,  and  a  small  quantity 
of  kainit.  This  method  was  first  used  by  the  Bavarian  Government. 

The  Ferrell  Process. — The  salts  selected  recombine  in  the  wood  as  in 
the  Thilmany  Process.  The  impregnation  is  manipulated  from  the  ends 
of  the  pieces  as  in  the  Boucherie  Method. 

The  Creoaire  Creosote  Process. — This  process,  which  is  designed  to 
overcome  the  tendency  of  creosote  to  lodge  near  the  surfaces  of  timbers, 
consists  in  subjecting  woods,  that  have  been  creosoted,  to  a  final  air 
pressure,  by  means  of  which  the  creosote  is  driven  in  from  the  surface 
and  deposited  more  evenly  throughout  the  mass.1 

WOODS  THAT  ARE  TO  RECEIVE  TREATMENT 

Some  woods  last  naturally  without  treatment  longer  than  other 
woods  will  last  after  they  have  been  treated. 

It  is  often  well  to  consider  the  economy  of  treating  non-durable 
woods  that  are  tough  and  strong  and  that  respond  to  treatment. 
For  example,  beech  is  desirable  structurally  save  for  the  fact  that 
it  rots  quickly  in  exposed  places;  yet  it  receives  antiseptic  solu- 
tions better  than  white  oak  receives  them  and,  after  being  suit- 
ably processed,  will  last  for  a  long  time. 

The  results  obtained  with  beech  by  the  French  are  often  quoted. 
Beech  ties  are  seasoned  for  at  least  six  months  and  are  then  kiln-dried 
for  from  sixty  to  eighty  hours  to  expel  the  remaining  moisture  and  to 
warm  the  pieces  so  that  they  will  not  chill  the  creosote.  Each  tie  then 
receives  an  average  of  sixty  pounds  of  creosote.  Experience  has  led  to 

1  Yet  occasionally  practised  by  the  International  Creosoting  and  Con- 
struction Company,  Galveston,  Texas. 


PRESERVATIVES  APPLIED  WITHIN  WOODS  375 

the  belief  that  such  ties  will  last  in  the  track  for  at  least  thirty  years, 
and  that  they  will  finally  fail  by  wear  rather  than  by  rot.1 

The  ability  of  wood  to  receive  preservative  treatment  is  influ- 
enced by  the  character  and  arrangement  of  its  cell-elements. 
The  presence  of  tyloses  in  the  large  vessels  or  pores  of  such  woods 
as  white  oak  and  black  locust  interferes  correspondingly  with  the 
treatment  of  these  woods.  As  a  rule,  sapwood  is  more  open  to 
the  passage  of  preservatives  than  is  heartwood.  Large  quantities 
of  yellow  pine  are  now  treated  with  preservative,  while  von 
Schrenk  suggests,  beech,  maple,  birch,  red  and  swamp  oaks,  gum, 
hemlock,  and  even  cottonwood  as  American  species  that  should 
receive  consideration  in  this  connection.2 

Individual  pieces,  as  well  as  species,  vary  from  one  another  in 
receptivity.  For  this  reason,  as  far  as  possible,  charges  should 
be  made  up  of  pieces  that  are  nearly  similar  to  one  another.  Re- 
fractory pieces  should  receive  such  special  attention  as  is  neces- 
sary to  overcome  extra  resistance. 

The  tendency  of  preservatives  to  lodge  near  the  surface  of 
pieces  should  be  recognized,  and,  whenever  possible,  timber 
should  be  cut,  shaped,  or  fitted  before  it  is  treated. 

CONCLUSIONS 

1.  Cheap  woods,  or  those  used  in  inexpensive  or  unimportant 
constructions,  are  seldom  treated  with  preservatives  at  the  present 
time  in  the  United  States.     Woods  are  now  treated  only  when 
they  become  costly,  or  when  they  are  to  be  used  in  works  that 
do  not  permit  renewals  or  repairs  at  reasonable  prices. 

2.  Zinc   chloride  and  creosote  are  used  more  than  all  other 
wood  preservatives. 

3.  Zinc  chloride  is  soluble  in  water,  and  therefore  cannot  be 
used  with  woods  that  are  to  be  exposed  in  marine  positions. 
Neither  is  it  known  that  it  protects  woods  against  marine  and 
terrestrial  woodborers.     The  principal  field  of  zinc  chloride  as  a 
wood  preservative  is  with  railway  ties  that  cannot  be  economically 
treated  with  the  more  expensive  creosote. 

4.  Experience  has  shown  that  wood  can  be  protected  against 
rot,  and  against  marine  and  terrestrial  woodborers,  by  the  intel- 
ligent use  of  sufficient  quantities  of  good  creosote. 

1  " Preservation  of   Railway   Ties  in   Europe,"    Chanute    (Transactions 
American  Society  of  Civil  Engineers,  Vol.  XLV,  1901). 

2  United  States  Department  of  Agriculture,  Yearbook,  1903  (p.  42). 


376  ORGANIC  STRUCTURAL  MATERIALS 

5.  Creosote  is  complex  and  variable.     It  should  therefore  be 
purchased  from  reputable  dealers,  and  its  properties  should  be 
controlled  by  specifications. 

6.  The  details  of  wood-preserving  processes  call  for  knowledge, 
skill,  and  integrity  on  the  part  of  the  operator.     A  poor  method 
well   detailed  may  afford  better  results  than  a  better  method 
poorly  detailed. 


CHAPTER  XV 

PROTECTIVE    METHODS — EXTERNAL     TREATMENT.       OILS, 

PAINTS,  VARNISHES,  AND  OTHER  COATINGS.     THEIR 

APPLICATION  TO  SURFACES  OF  WOOD 

Outside  coatings  not  only  protect  from  outside  conditions,  but 
at  the  same  time  seal  up  any  moisture  that  may  be  present  within 
the  wood.  Moisture  thus  enclosed  makes  rotting  possible. 
Furthermore,  since  oil  and  water  do  not  mix,  paints  will  not  be- 
have in  a  satisfactory  manner  if  applied  to  woods  that  are  wet. 
It  therefore  follows  that  no  coating  of  any  kind  should  be  ap- 
plied to  wood  that  is  not  dry  and  well  seasoned. 

External  coatings,  which  are  of  many  kinds,  are  employed  both 
to  beautify  woods  and  to  protect  them  against  marine  life  and 
abrasion,  as  well  as  moisture  and  the  decay  caused  by  bacteria 
and  fungi.  Woods  may  be  enclosed  by  metal,  plaster,  masonry, 
and  charcoal,  as  well  as  by  paints  and  varnishes. 

A  protective  coating  is  not  always  decorative,  but  a  decora- 
tive coating  always  affords  protection.  Paint  is  a  Material  of 
Construction,  and  its  behavior  in  construction  is  quite  as  impor- 
tant as  its  color  or  appearance.  The  durability  of  any  coating 
must  generally  influence  that  of  the  substance  which  it  covers. 

The  cost  of  the  most  expensive  coating  is  generally  less  than 
the  present  cost  of  the  labor  required  to  apply  it,  and  the  more 
intricate  the  surface,  the  greater  the  disproportion  between  the 
bill  for  labor  and  the  bill  for  material.  True  economy  consists 

REFERENCES. — "White  Lead  and  Zinc  Paints,"  Petit  (Scott,  Greenwood 
&  Sons,  London,  1907);  "Lead  and  Zinc  Pigments,"  Holley  (Wiley  &  Sons, 
1909);  "Linseed  Oil,"  Ennis  (Van  Nostrand,  1910);  "Chemistry  of  Paints," 
Friend  (Longmans,  Green  &  Company,  1910);  "Materials  of  the  Painters' 
Craft,"  Laurie  (Foulis,  London  and  Edinburgh,  1910);  "German  and 
American  Varnish-Making,"  Bottler  and  Sabin  (Wiley  &  Sons,  1912); 
"Technology  of  Paint  and  Varnish,"  Sabin  (John  Wiley  &  Sons,  1917); 
Files  of  Painters'  Magazine;  Oil  and  Color  Trades  Journal;  Proceedings  of 
the  Paint  and  Varnish  Society  (London);  Farben-Zeitung  (Berlin);  Engineer- 
ing News;  Engineering  Record;  Railway  Gazette;  Transactions  American 
Society  for  Testing  Materials;  Journal  Industrial  and  Engineering  Chemistry 
(American  Chemical  Society). 

377 


378  ORGANIC  STRUCTURAL  MATERIALS 

in  selecting  the  paints  and  other  materials  that  last  longest,  so 
that  there  will  be  the  longest  possible  intervals  between  renewals. 

Woods  that  are  to  be  coated  may  be  within  doors,  protected 
from  the  weather,  or  out  of  doors,  exposed  to  the  weather. 
Polished  surfaces,  enamels,  fine  varnishes,  and  ordinary  oil 
paints  are  common  in  the  case  of  interior  surfaces,  while  oil  paints 
predominate  in  connection  with  exteriors,  which  are  much  simpler 
in  their  requirements.  Ships,  passenger  cars,  carriages,  furni- 
ture, and  some  other  constructions  require  special  methods,  that 
are  distinct  from  the  simple  protection  of  ordinary  woodwork 
by  paint. 

The  behavior  of  a  paint  when  applied  to  unpainted  wood 
differs  from  its  behavior  when  applied  to  unpainted  metal. 
Paint  sinks  into  the  pores  of  clean,  dry  wood  to  an  extent  that  is 
not  possible  with  metal.  Woods  themselves  differ  in  receptivity, 
the  loose-grained  species  absorbing  the  paint  more  readily  than 
do  those  with  the  closer  grain. 

PAINT. — A  paint  is  a  mixture  of  a  vehicle  and  a  pigment. 
Although  oil,  varnish,  glue,  or  any  other  fluid  that  will  cement 
solid  particles  together  in  a  satisfactory  manner,  may  be  em- 
ployed as  a  vehicle,  linseed  oil  is  the  common  vehicle  in  the 
paints  that  are  used  in  construction. 

A  pigment  is  a  more  or  less  inert  base  that  will  join  with  oil 
to  form  a  paint.  The  function  of  the  vehicle  is  to  cement  and 
give  strength,  while  the  pigment  serves  to  afford  solidity,  color, 
and  hardness.  White  lead,  zinc  white,  and  the  iron  oxides  are 
among  the  basic  pigments  that  are  commonly  applied  to  woods. 

A  paint  is  a  mechanical  mixture  or  suspension,  rather  than  a 
chemical  combination.  Paint,  as  a  substance,  fails  when  changes 
take  place  in  the  dried  vehicle  or  binding  material.  As  a  coating, 
paint  may  fail  by  abrasion,  as  by  rain  or  dust,  by  contraction, 
expansion,  and  cracking,  or  because  it  has  been  applied  to  surfaces 
that  were  not  clean  and  dry. 

VARNISH. — Varnish  is  obtained  by  dissolving  resins  in  oil  or 
spirit.  Oil  varnish  differs  from  spirit  varnish,  in  that  oil  takes 
a  permanent  place  as  part  of  the  dried  film;  whereas  spirit  simply 
dissolves  the  varnish  resins  and  then  evaporates  from  them. 
The  mixture  that  results,  when  pigment  is  added  to  varnish,  is 
known  as  an  enamel  or  varnish  paint.  In  such  paints,  varnish, 
instead  of  oil,  is  the  vehicle. 

Varnishes  are  solutions,  and  thus  differ  from  paints,  which 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS     379 

are  mechanical  mixtures.  A  paint  may  or  may  not  be  prepared 
by  the  consumer,  but  a  high-grade  varnish,  which  can  be  manu- 
factured only  by  a  chemical  process,  can  seldom  be  prepared  by 
the  consumer. 

The  subject  is  one  that  must  be  considered  in  three  parts, 
namely:  the  materials  of  which  paints  and  varnishes  are  com- 
posed; the  methods  used  to  apply  paints  and  varnishes;  with  the 
influence  of  such  methods  upon  durability;  and  the  preparation 
of  woods  to  receive  paints  and  varnishes. 

MATERIALS  USED  IN  PAINTS  AND  VARNISHES 

OILS. — All  oils  used  in  constructions  may  be  divided  into 
three  groups;  solidifying  oils,  that  can  be  used  in  paints  because 
they  change,  upon  exposure,  into  tough,  leathery  solids;  non- 
solidifying  oils,  that  are  not  used  in  paints  and  that  are  men- 
tioned in  this  place  only  for  completeness;  and  volatile  oils  or 
spirits,  that  serve  to  dissolve  or  to  dilute  paints. 

Solidifying  Oils  and  Driers. — Solidifying  oils  do  not  dry  in 
the  ordinary  sense  of  the  word,  because  of  loss  of  water,  but 
because  of  chemical  changes  which  they  undergo  when  they  are 
exposed  to  the  air  at  ordinary  temperatures  and  in  thin  sheets. 
Oil  from  walnuts  and  oils  from  other  sources  possess  this  property, 
but  oil  from  common  flaxseed  is  preferred  for  ordinary  condi- 
tions, both  because  it  affords  good  results,  and  because  it  can  be 
obtained  in  commercial  quantities  at  reasonable  cost.  The 
Chinese  Tung  Oil  is  also  very  valuable. 

Linseed  Oil. — Linseed  oil  is  drawn  from  the  seed  of  the  flax  plant  by 
hot  or  cold  pressure,  or  by  solvents,  and  is  then  treated  to  a  process  of 
purification.  The  tough,  elastic,  semi-translucent  solid,  into  which  this 
oil  changes  upon  exposure,  is  known  as  linoxyn  or  oil-rubber.1  This 
solidified  or  " dried"  compound,  although  occupying  smaller  space,  has 
increased  in  weight  from  ten  to  eighteen  per  cent.,  because  of  oxidation 
or  other  changes  that  have  taken  place. 

Pure,  raw  linseed  oil  requires  some  days  to  solidify.  This  time  may 
be  reduced  by  boiling  the  raw  oil  with  certain  metallic  salts,  or  by  adding 
compounds,  known  as  driers,  to  the  raw  oil.  In  each  case  the  object 

1  Although  linoxyn  or  oil-rubber  is  not  nearly  as  elastic  as  true  rubber,  it 
has  been  used  with  true  rubber.  The  "drying"  or  solidification  of  linseed 
oil  has  presented  many  problems  and  is  described  in  "Some  New  Points  in 
Paint  Technology,"  Sabin  (Laboratory  Bulletin,  January  31,  1911).  See 
also  "Linseed  Oil,"  Ennis  (D.  Van  Nostrand  Company).  , 


380  ORGANIC  STRUCTURAL  MATERIALS 

of  the  metallic  salt,  or  other  drier,  is  to  act,  as  a  catalyzer,  by  transferring 
oxygen  from  the  air  to  the  oil.  Raw  oil  with  added  drier  is  often  referred 
to  as  boiled  oil,  even  although  it  has  not  been  boiled. 

Raw  linseed  oil  penetrates  better  and  is  more  durable  than  boiled  oil, 
or  oil  to  which  a  drier  has  been  added;  but,  since  the  weather  cannot  be 
relied  upon  to  remain  clear  long  enough  for  raw  oil  to  dry,  drying  should 
be  hastened  by  adding  the  smallest  possible  quantity  of  drier  to  the 
raw  oil. 

A  product  prepared  by  heating  refined  linseed  oil,  without  driers, 
until  it  has  become  thick  and  viscous,  but  not  jelly-like,  is  known  as 
lithographic  oil.  This  product,  the  use  of  which  is  rapidly  increasing, 
is  employed  in  varnishes  as  well  as  in  printers'  ink. 

Tung  Oil,  China  Wood  Oil,  Elaeococca  Oil— This  oil,  which  is  de- 
rived from  the  seeds  of  the  Tung  Oil  tree  (Akurites  fordii},1  has  long 
been  employed  in  the  Orient,  for  waterproofing  and  other  purposes. 
The  Chinese  have  used  it  to  waterproof  their  umbrellas,  and  to  prepare 
paper  so  it  could  be  used  for  glazing. 

Tung  Oil  is  a  drying  oil  of  the  very  first  value;  and  its  position  as  a 
Material  of  Construction  is  more  and  more  realized  in  the  United  States, 
to  which  country  large  quantities  are  now  brought  every  year.  Within 
a  few  years  it  has  largely  displaced  the  use  of  linseed  oil  in  the  manu- 
facture of  certain  varnishes,  that  are  valued  because  they  dry  more 
rapidly  than  linseed  oil  varnishes,  because  they  are  not  liable  to  crack, 
and  because  they  ultimately  present  tough,  durable,  alkali-resisting, 
flat,  that  is  not  glossy,  surfaces.  Tung  Oil.  is  used  in  flat  wall  finishes 
and,  in  mixtures,  to  waterproof  cements.  The  oil  possesses  a  strong, 
characteristic  odor  which  is  largely  removed  during  the  cooking  and 
manipulating  that  it  receives  while  being  manufactured  into  varnish. 
Sandalwood  oil,  cedar  oil,  citronella,  and  other  chemical  compounds 
are  sometimes  used  in  the  attempt  to  smother  this  odor,  but  they  do 
not  succeed  because  they  so  largely  evaporate. 

Driers. — Driers  should  be  purchased  from  reputable  dealers,  and 
should  be  used  in  the  smallest  possible  quantities.  Sabin  states  that 
although  drier  injures  paint,  yet  "the  lack  of  it  is  fatal,  for  paint  must 
dry  within  a  reasonable  time."  Driers  carry  oxygen  throughout  the 
depth  of  the  coat.  Oxides  of  lead  and  manganese  are  fundamental 
driers.  Chemically,  driers  are  catalytic  agents. 

A  japan  drier  cannot  be  definitely  distinguished  from  other  driers, 
although  the  name  japan  usually  refers  to  driers  that,  with  other  proper- 

1  "The  China  Wood  Oil  Tree,"  Fairchild  (United  States  Bureau  of  Plant 
Industry,  Circular  No.  108);  Files  of  Oil,  Paint  and  Drug  Reporter;  "Index 
of  Patents,  Technology,  and  Bibliography  of  China  Wood  Oil  (Tung  Oil)," 
George  H.  Stevens  and  J.  Warren  Armitage  (Published  by  Authors  at 
Irvington  and  Newark,  New  Jersey,  1914). 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      381 

ties,  are  characterized  by  the  fact  that  they  will  harden  into  varnish-like 
films.  Japan  varnishes  are  called  after  the  country  in  which  they  orig- 
inated. The  name  japan  may  apply  to  a  drier  or  to  a  varnish.  Most 
driers  are  "  proprietary  mixtures." 

Non-solidifying  Oils. — Oils  of  this  class  are  mentioned  for 
completeness.  These  oils  are  not  used  in  paints,  but  some  semi- 
solidifying  oils — that  respond  to  the  action  of  driers — are  used 
for  this  purpose,  particularly  in  prepared  paint  mixtures.  Non- 
solidifying  oils  are  used  as  lubricants  which  serve  to  fill  the  minute 
inequalities  that  exist  on  the  surfaces  of  all  machine  materials 
and,  therefore,  should  not  under  any  circumstance  solidify 
or  "gum."  Although  lubricating  oils  are  manufactured  princi- 
pally from  petroleum,  the  group  also  includes  whale,  olive,  lard, 
and  many  other  oils. 

Volatile  Oils  and  Spirits. — Turpentine,  benzine,  benzole,  and 
alcohol  are  the  volatile  oils  and  spirits  most  used  with  paints 
and  varnishes.  Turpentine  contains  a  small  proportion  of 
gummy  cementing  substance  that  eventually  becomes  part  of 
the  finish.  Benzine  and  alcohol  vaporize  completely  without 
leaving  residues. 

The  excessive  use  of  volatile  solvents  injures  paints  because 
they  thin  the  oils  upon  which  paints  depend  for  their  strength. 
A  thinned  paint  spreads  easily  and  covers  a  greater  surface,  but 
the  dried  film  is  correspondingly  thinner.  A  thinned  paint  dries 
rapidly,  but  is  less  durable.  Turpentine  may  cause  direct  injury 
to  exactly  prepared  paint  mixtures,  and  should  seldom  normally 
be  employed  in  any  outside  or  weather  coat. 

Volatile  solvents  are  of  advantage  when  paints  are  to  be 
applied  to  close-grained  woods  or  to  already  existing  hardened 
paint.  Pure  oil  is  too  thick  to  sink  sufficiently  into  many  woods, 
while  old  paint  is  often  so  hard  that  paint  without  turpentine 
will  not  adhere. 

PIGMENTS. — A  pigment  contributes  thickness,  opacity, 
hardness,  solidity,  and  color.  Oil  binds  the  particles  of  pigment 
together,  as  stones  are  bound  in  concrete,  and  pigment  thickens 
the  oil.  The  hard  particles  of  pigment  assist  the  paint  in 
resisting  abrasion. 

Oil  shrinks  in  drying;  and  the  minute  openings  that  are  formed 
would  cause  the  coating  to  become  porous,  if  it  were  not  for  the 
particles  of  pigment  used  to  fill  them.  The  openings  are  very 
small,  and  the  pigment  should  be  in  correspondingly  fine  pow- 


382  ORGANIC  STRUCTURAL  MATERIALS 

der.  Pigments  are  also  relied  upon  to  produce  exact  colors. ]  The 
principal  pigments  used  in  paints  that  are  applied  to  woods  are 
white  lead,  zinc  white,  the  iron  oxides,  and  carbon. 

White  Lead.— Approximately  2PbC03.Pb(OH)2.  This  opaque, 
heavy,  white  pigment  is  usually  ground  in  a  small  quantity  of  oil  and 
sold  as  a  paste,  with  which  the  necessary  additional  quantities  of  oil  are 
later  mixed.  White  lead  mixes  well,  works  easily  under  the  brush,  and 
is  in  every  way  the  most  satisfactory  of  the  white  pigments,  although 
less  durable  than  some  that  are  not  white.  Any  tint  may  be  produced 
by  adding  the  proper  pigment  to  a  body  paint  of  white  lead. 

White  lead  ultimately  degenerates  into  a  form  that  permits  a  chemical 
union  to  take  place  between  it  and  the  oil.  This  change  takes  place 
much  more  rapidly  in  some  cases  than  in  others.  White  lead  lasts  longer 
within  houses,  or  in  the  country,  than  upon  the  outside  of  houses,  or 
in  the  city.  White  lead  " chalks"  very  rapidly  near  the  seashore. 

White  lead  as  a  coat  fails,  as  other  coats  do,  by  contraction  and  ex- 
pansion, with  resulting  cracking  and  peeling,  much  of  which  can  be 
postponed  by  judicious  mixing  and  application.  In  spite  of  defects,  no 
other  white  base  has  as  yet  been  discovered  that  presents  many  of  the 
properties  that  render  white  lead  so  desirable. 

Zinc  White  (ZnO). — Oxide  of  zinc  is  prepared  by  roasting  metallic 
zinc,  01;  non-sulphurous  zinc  ores,  and  by  permitting  the  vapors  that 
result  in  either  case  to  combine  with  atmospheric  oxygen.  Zinc  white 
is  lighter,  harder,  whiter,  and  less  changeable  than  white  lead;  but  it 
requires  more  oil  and  does  not  spread  as  well  as  white  lead;  neither  does 
it  adhere  as  well  as  that  pigment.  Three  coats  of  white  lead  are  usually 
equal  to  five  coats  of  zinc  white.  Zinc  white  and  white  lead  may  be 
mixed  together  with  advantage. 

Barium  Sulphate  (BaS04). —Barium  sulphate,  barytes,  or  heavy  spar, 
is  a  heavy,  brittle,  white  or  light-tinted  mineral  that  is  capable  of  being 
ground  to  a  smooth,  colorless,  and  chemically  inert  powder.  It  is  often 
affirmed  that  this  substance  is  used  as  an  adulterant;  but,  if  this  is  so, 
it  does  not  greatly  injure  the  paint.  It  is  a  cheaper  base  than  are  lead 
or  zinc  pigments,  but  more  coats  are  needed  if  the  work  is  to  present  as 
solid  and  opaque  an  appearance.  The  field  for  pure  barium  paints  has 
been  limited. 

1  The  principal  colors  are  produced  by  the  following  pigments : 

White White  lead,  zinc  white. 

Black Lamp  black. 

Red Red  lead. 

Blue Ultramarine  and  Prussian  blue. 

Yellow Chrome  yellow  (lead  chromate  PbCrO4). 

Green Chrome  green  (chromium  sesquioxide). 

Brown,  red-brown,  etc The  siennas,  umbers,  etc. 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      383 

A  pigment  should  be  opaque  when  it  is  wet.  Even  ground  glass  is 
white  and  opaque  as  long  as  it  is  dry,  but  loses  much  of  its  opacity  when 
water  is  added.  Barium  sulphate,  silica,  and  some  other  pigments 
otherwise  satisfactory  lose  much  in  this  connection  when  compared  with 
white  lead  or  zinc  white,  although  otherwise  some  of  them  compare 
favorably  with  those  pigments. 

There  are  other  white  pigments.  As  some  clays  are  used  for  making 
bricks,  and  others  are  used  for  making  porcelains,  so  certain  fine  white 
clays,  known  as  china  clays,  are  dried,  ground  and  used  as  pigments. 
Painters'  silica  and  ground  quartz  are  the  same.  Infusorial  earth  is 
too  fine  to  serve  as  a  pigment,  but  has  been  used  with  more  or  less  success 
in  fillers. 

Red  Lead  (Pb304). — Red  lead  is  made  by  oxidizing  litharge  (PbO), 
and  often  contains  from  one  per  cent,  to  as  much  as  twenty-five  per  cent, 
of  residual  litharge.  If  much  litharge  is  present,  the  linseed  oil  used  in 
mixing  does  not  change  to  linoxyn;  but,  in  this  case,  a  lead  compound 
is  apparently  formed,  and  the  oil  and  pigment  harden,  even  although 
shut  in  from  the  air.  True  red  lead,  that  is,  red  lead  without  residual 
litharge,  and  oil  remain  mixed  for  years  without  reaction.  The  United 
States  Government  now  specifies  that  the  product  known  as  "red  lead" 
must  contain  at  least  ninety-four  per  cent,  of  true  red  lead  (Pb304), 
and,  for  some  uses,  specifies  ninety-eight  per  cent,  or  even  a  larger  pro- 
portion of  true  red  lead.  For  under- water  use  red  lead  paints  should 
be  mixed  with  genuine  boiled  oil.  Red  lead  paints  usually  adhere  to 
iron  with  great  tenacity.  In  the  United  States  they  are  seldom  used 
on  wood,  except  as  it  contains  pitch;  but  in  foreign  countries  red  lead, 
paints  are  often  used,  as  other  paints  are  used,  to  prime  woods.1 

Iron  Oxides  (Fe203  and  variously  hydrated  oxides) . — Iron  oxides  may 
be  natural  or  artificial.  Natural  oxides  result  from  hematites  and  limon- 
ites.  Those  from  the  former  mineral  are  harder,  more  costly  to  grind 
and  have  more  or  less  dull,  brownish-red  colors;  while  the  softer  limon- 
ites  present  a  series  of  somewhat  lifeless  yellows.  Natural  ores  vary 
greatly  in  their  adaptability  for  use  as  pigments,  chemical  and  physical 
peculiarities  being  responsible  for  many  grades  and  colors.  Sienna  is  one 
of  the  most  brilliant  of  these  ferruginous  earth  colors.  The  ochres  and 
umbers  are  also  among  them.  Many  natural  ores  are  roasted  before 
they  are  ground.  Umber  when  thus  roasted  is  known  as  burnt  umber. 

Ordinary  iron  oxide  paints  are  applied  to  both  woods  and  metals. 
They  spread  well,  adhere  firmly  to  wood  and  are  very  durable.  They 
are  often  preferred  for  large  surfaces  of  wood  that  are  to  be  covered 
without  much  regard  to  color.  Natural  oxide  paints  are  thus  used  on 
freight  cars,  sheds  and  barns;  while  the  finer,  more  attractive  grades, 
with  some  of  those  that  are  manufactured  artificially,  such  as  Tuscan 

'See  also  "Red  Lead,"  Sabin  (Author's  Edition). 


384  ORGANIC  STRUCTURAL  MATERIALS 

and  Indian  reds,  are  used  upon  residences  and  passenger  coaches.  The 
field  is  a  large  one,  and  covers  many  grades  or  kinds  of  paint.  Consider- 
able quantities  of  oxide  paints  are  used  on  steel  structures,  but  such 
paints  for  this  purpose  are  giving  place  in  many  sections  to  carbon  paints. 

Carbon  (C). — Carbon  is  a  chemically  inert  substance,  and  is,  therefore, 
well  adapted  for  use  on  iron.  Lamp  black,  bone  black,  ivory  black, 
and  graphite  are  the  forms  most  used  in  paint.  Carbon  is  seldom  used 
for  the  body  of  a  paint  to  be  applied  to  wood,  but  rather  to  tint  such  a 
paint.  It  is  largely  used  on  metal.  Lamp  black,  obtained  from  the 
imperfect  combustion  of  oil,  is  so  bulky  that  a  barrelful  may  weigh  less 
than  twenty  pounds.  It  requires  more  oil  than  other  pigments,  and 
causes  the  paint  to  dry  slowly,  because  of  a  small  proportion  of  non- 
drying  oil  which  it  frequently  contains;  pure  lamp  black  is  neutral,  and 
neither  retards  nor  assists  in  the  drying  of  the  oil.  A  paint  of  lamp 
black  is  one  of  the  most  durable  of  all  paints. 

Common  graphite  is  laminated  even  after  it  has  been  ground  into 
small  particles;  and  the  manufacturers  who  use  it  state  that  the  minute 
particles  arrange  themselves  when  in  paint,  overlapping  one  another* 
much  as  scales  do  upon  the  sides  of  a  fish.  Certainly,  the  particles  are 
very  fine,  and,  regardless  of  their  arrangement,  the  fact  exists  that  some 
paints  of  this  class  are  very  durable  when  laid  upon  iron.  Most  Ameri- 
can graphite  is  mixed  so  intimately  with  the  rock  in  which  it  occurs 
that  all  of  the  rock  cannot  be  removed.  The  silica  present  does  not 
appear  to  exert  an  injurious  influence,  however.  Personal  preference 
must  be  exercised  in  choosing  between  the  several  forms  of  graphite 
and  lamp  black  paints.1 

FILLERS. — Woods  are  more  or  less  porous,  and  should  be 
primed  before  ordinary  paints  are  applied  to  them,  not  only  be- 
cause paints  of  normal  thickness  cannot  penetrate  sufficiently  to 
attach  themselves  to  woods,  but  also  because  a  porous  wood  tends 
to  separate  oil  from  pigment.  The  materials  or  mixtures  used  for 
priming  woods  should  accord  with  the  coatings  that  are  to  be 
applied  later.  Some  mixtures  will  not  adhere  to  others.  Some- 
times treatment  that  prepares  for  paint  does  not  prepare  equally 
for  varnish,  and  sometimes  the  same  treatment  does  for  both. 
Oils,  varnishes,  thin  paints,  and  prepared  fillers  are  all  used  to 
prime  or  to  fill  woods  that  are  to  be  painted  or  varnished. 

Woods  that  are  to  be  painted  should  be  primed  or  filled  with  thin 
paint  or  pure  linseed  oil.  Sabin  states  that  "the  best  filler  for  wood 
that  is  to  receive  ordinary  oil  paint  is  a  coat  of  linseed  oil."  This  sinks 
into  the  wood  and  fills  pores  that  might  otherwise  separate  the  oil  from 

1  An  interesting  material,  in  the  nature  of  an  amorphous  graphite,  which 
is  known  as  Acheson  graphite,  is  manufactured  from  coal  in  electric  furnaces 
by  the  Sherwin-Williams  Company. 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      385 

the  pigment  when  the  full  paint  is  later  applied.  It  affords  a  base  to 
which  the  paint  will  adhere,  and  reduces  the  tendency  to  scale.  Even 
pure  oil  is  sometimes  too  thick  and  heavy  to  sink  into  some  woods,  and 
must  be  thinned  by  turpentine,  in  order  to  secure  the  proper  degree  of 
penetration.  When  pure  oil  is  used  for  priming,  it  often  becomes  hard 
to  determine  whether  some  portion  of  the  work  has  not  been  overlooked, 
since  there  is  but  little  difference  in  the  appearance  of  unprimed  parts 
and  parts  primed  with  pure  oil.  The  small  quantity  of  pigment  which 
is  commonly  added  to  the  oil  gives  color  to  the  wood  and  removes  this, 
danger.  Moreover,  a  little  pigment  assists  by  penetrating  and  filling 
the  pores  of  the  wood. 

A  filler  must  be  of  such  a  nature  that  it  will  enter  the  wood,  and  then, 
like  the  cement  used  by  dentists,  dry  without  shrinking.  Proprietary 
fillers  are  manufactured  from  silica,  powdered  bark,  white  lead,  or  other 
substances  combined  with  oil  or  varnish.  Paste  fillers  are  better  than 
liquid  fillers,  although  the  latter  are  more  convenient. 

Varnish  itself  is  often  used  to  fill  woods  that  are  to  be  varnished  or 
polished,  and  is  an  excellent,  although  expensive,  filler.  A  priming 
varnish  should  be  thin,  so  that  it  will  sink  into  the  wood.  Spar  varnish 
is  often  thus  laid  directly  upon  wood  that  is  to  be  exposed  to  the  weather. 
Other  coats  of  varnish  are  added  until  a  firm  and  durable  case  is  built  up. 

GUMS,  RESINS  AND  VARNISHES.— True  gums  dissolve 
in  water,  while  true  resins  dissolve  in  oil  or  spirit.  There  are 
also  gum- resins,  parts  of  which* dissolve  in  oil  and  parts  in  water; 
and  yet  other  exceptions,  as  india  rubber,  that  dissolve  in  special 
solvents,  such  as  carbon  bisulphide. 

The  name  resin  is  seldom  heard  among  varnish-makers,  and, 
commercially,  the  name  gum  is  applied  to  many  substances  that 
are  really  resins.  True  gums,  such  as  gum-arabic,  are  not  em- 
ployed in  the  manufacture  of  varnishes  that  are  to  be  used  on 
woods.  A  solution  of  true  gum  in  water  is  called  a  mucilage. 

Varnish  resins  have  been  roughly  divided  into  fossil,  semi- 
fossil,  and  fresh-product  resins.  The  origin  of  many  fossil  and 
semi-fossil  resins  is  uncertain.  Amber  is  a  fossil  resin,  while 
dammar,  mastic,  and  pine  resins  are  among  the  fresh-product 
resins. 

Varnish  resins  may  also  be  roughly  divided  into  those  used 
with  oil  and  those  used  with  spirit.  Kauri  resin  is  thus  preferred 
in  oil  varnish,  while  shellac,  dammar,  and  mastic  are  among 
those  used  in  spirit  varnishes.  The  distinction  between  oil  and 
spirit  as  solvents  has  been  noted  in  the  section  devoted  to  oils. 

Most  varnish  resins  are  classified  from  the  geographical  or 


386  ORGANIC  STRUCTURAL  MATERIALS 

physical  standpoint  rather  than  from  that  of  exact  botanical 
origin.  As  the  wood  known  in  trade  as  " cedar"  may  come  from 
several  species,  so  varnish  resins  may  be  grouped  by  experts 
without  reference  to  the  trees  from  which  they  came.  Amber  is 
said  to  represent  about  fifty  extinct  botanical  species.  Time  and 
the  process  of  mineralization  have  doubtless  obliterated  many 
minor  distinctions  due  to  species. 

Statements  found  in  the  literature  of  this  subject  are  often 
contradictory  and  misleading,  but  it  is  certain  that  characteristics 
do  exist  that  enable  experts  to  classify  these  products  and  to 
estimate  their  value  for  varnishes.  Resins  are  often  called  by 
different  names  in  different  places,  but  reputable  manufacturers, 
guided  by  their  own  standards,  make  selections  that  enable 
them  to  present  uniform  and  reliable  varnishes. 

Most  fossil  resins  must  be  heated  before  the  changes  take 
place  that  enable  them  to  yield  to  the  solvents  employed  by 
varnish  makers.  Temperature,  the  proportions  of  resins  and 
solvents,  the  combinations  of  resins  with  one  another,  and  other 
details  are  important  in  the  formation  of  tough,  hard,  durable, 
and  otherwise  desirable  mixtures. 

Amber. — This  hard  and  costly  mineralized  resin  is  found  in  small, 
detached  masses,  in  a  few  alluvial  deposits.  The  total  annual  yield  of 
the  important  Baltic  field  is  said  to  be  less  than  one  hundred  and  fifty 
tons.  The  best  pieces  are  used  for  ornamentation,  beads,  and  the  mouth- 
pieces of  pipes,  while  refuse,  or  black  amber,  is  said  to  be  manufactured 
into  special  varnishes  that  can  be  used  for  the  protection  of  oil  paintings. 

Copal. — This  name  is  applied,  without  regard  to  botanical  or  geo- 
graphical origin,  to  a  wide  range  of  resins  used  in  the  manufacture  of 
varnishes.  When  classified  geographically,  copals  take  name  from  ports 
of  shipment,  and  are  described  as  Manila,  Zanzibar,  Sierra  Leone,  South 
American,  or  other  copals.  They  are  also  sometimes  divided  into  true 
and  false  copals,  the 'former  including  the  harder,  more  lustrous,  and 
refractory  products,  and  the  other,  those  that  are  softer,  more  variable, 
and  more  easily  dissolved.  It  will  be  seen  that  the  name  copal  is  a 
general  one,  the  value  of  which  cannot  be  exactly  told  save  from  its 
context. 

Anime. — This  is  also  a  general  name,  which,  although  often  seen, 
means  very  little  to  modern  varnish  makers. 

Zanzibar. — This  is  one  of  the  hardest,  most  brilliant,  and  most  per- 
manent resins  available  to  varnish-makers.  With  other  resins,  it  enters 
into  the  durable  mixture  known  as  "spar  varnish;"  and  also  into  most 
of  the  good  varnishes  designed  for  interiors.  It  is  an  ingredient  of  some 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      387 

of  the  most  satisfactory  piano  varnishes.  Zanzibar  resin  is  considered 
wherever  a  high  degree  of  hardness,  brilliancy,  and  permanence  is 
desired. 

Kauri. — Fossil  kauri  is  collected  by  digging  over  fruitful  areas  from 
which  parent  trees  have  disappeared,  while  fresh  kauri  is  obtained  from 
the  living  Kauri  Pine  (Dammara  australis}.  The  best  fossil-kauri  is 
one  of  the  most  valuable  constituents  of  good  oil  varnish,  since  it  pos- 
sesses the  property  of  uniting  with  linseed  oil  more  perfectly,  and  at 
lower  temperatures,  than  most  of  the  resins  now  employed  in  the  manu- 
facture of  varnish. 

Shellac. — This  valuable  fresh-product  resin  is  obtained  from  deposits 
found  upon  twigs  and  small  branches  of  certain  East  Indian  trees  (such 
as  Croton  lacciferus).  The  crude  exudations  known  as  lac  are  believed 
to  have  resulted  from  the  stings  of  peculiar  insects  often  found  imbedded 
in  the  twigs  and  branches. 

The  exudations,  which  are  divided,  according  to  form,  into  stick  lac 
and  seed  lac,  are  purified,  melted,  and  finally  spread  upon  flat  surfaces 
to  cool.  The  resulting  sheets  or  shells  are  known  as  "shellac."  Shellac 
is  the  principal  constituent  of  sealing  wax;  and  it  is  used  for  other  pur- 
poses, but  principally  in  spirit  varnish. 

Shellac  is  valued  in  construction  because,  when  applied  with  alcohol, 
it  is  not  influenced  by  any  resins  that  may  be  within  the  wood.  Oil 
paints  should  not  be  applied  directly  to  resinous  woods;  and  knots  should 
always  be  coated  with  shellac  before  they  are  painted.  Shellac  varnish 
is  valued  in  this  field  because  it  dries  so  rapidly  that  resins  do  not  have 
time  to  mix  with  it.  Shellac  varnish  is  more  or  less  influenced  by  water 
which  leaves  white  spots  wherever  it  is  permitted  to  stand  long  upon  the 
coat.  Shellac  is  prepared  by  dissolving  four  or  five  pounds  of  shellac 
in  a  gallon  of  alcohol,  and  should  be  thinned  whenever  necessary. 

Sandarack. — This  fresh  product  resin  is  obtained  from  trees  (Callitris 
quadrivalvis)  which  are  native  in  Morocco  and  other  districts  along  the 
north  African  coast.  There  are  also  independent  Australian  and 
Tasmanian  sandaracks.  It  is  a  rather  brittle  and  transparent  product, 
and  is  used  to  some  extent  in  the  preparation  of  a  fairly  hard,  pale, 
spirit  varnish,  suitable  for  light-colored  woods.  The  resin  is  one  of 
those  used  in  finishing  pianos. 

Sandarack  was  known  to,  and  was  used  by,  the  ancients  in  their 
ointments  and  incense.  In  powdered  form  it  was  once  dusted  over 
mural  decorations,  to  which  it  was  later  fixed  by  the  application  of 
heated  irons.  Powdered  sandarack  was  the  English  " pounce"  that 
was  applied  from  pounce  or  poncet  boxes  to  paper  from  which  erasures 
had  been  made. 

Dammar. — Some  of  the  rather  soft,  friable,  white  resins,  classed  under 
this  name  are  said  to  be  obtained  from  the  species  Dammara  orientalis. 
As  shellac  is  a  type  of  the  resins  that  serve  with  alcohol,  so  dammar  is 


388  ORGANIC  STRUCTURAL  MATERIALS 

a  type  of  those  that  serve  with  turpentine.  Dammar  is  popular  because 
of  the  ease  with  which  it  can  be  dissolved.  It  enters  the  whitest  varn- 
ishes and  is  a  medium  in  some  white  enameled  paints.  It  is  often  hard- 
ened by  the  addition  of  other  substances. 

Mastic. — This  fresh  product  resin  is  obtained,  in  part  at  least,  from 
the  species  Pistacia  lentiscus,  which  grows  in  many  Mediterranean 
countries.  It  is  fairly  clear  and  brittle,  but  becomes  white  and  plastic 
when  masticated,  hence  the  name  mastic.  It  dissolves  in  volatile  solv- 
ents and  serves  in  spirit  varnishes,  some  of  which  are  used  to  protect 
oil  paintings. 

Rosin. — Common  pine-rosin,  or  colophony,  known  as  rosin,  is  one  of 
the  poorest  and  cheapest  of  fresh-product  resins,  and  is  obtained  by 
distillation  from  crude  turpentine.  Rosin  when  hardened  artificially 
serves  as  a  base  in  most  cheap  varnishes.  Rosin  varnish,  when  first 
applied,  appears  brilliant  and  glassy,  but  soon  fades;  cracks  appear, 
and  the  varnish  eventually  scales  from,  the  wood.  The  addition  of  oil 
will  postpone  this  result. 

The  manufacture  of  varnish  calls  for  strict  integrity,  as  well 
as  much  skill,  on  the  part  of  the  manufacturer.  A  varnish  of 
cheap  pine-resin  can  be  made  to  resemble,  in  appearance,  one 
prepared  from  high-priced  kauri.  The  proportions  of  oil  and 
other  solvents,  and  the  uses  to  which  the  mixture  is  to  be  put, 
are  also  important.  It  is  usually  better  to  refer  the  use  to  which 
the  varnish  is  to  be  put,  to  the  manufacturer,  who,  upon  receiv- 
ing such  a  statement,  will  submit  the  mixture  that  is  most  likely 
to  succeed. 

Some  Miscellaneous  Materials. — Stains  are  dyes  employed  to  change 
the  natural  color  of  woods.  They  do  not  conceal  the  woods  as  paints 
do,  and  differ  from  both  paints  and  varnishes  in  that  they  do  not  form 
coatings.  Stains  influence  durability  only  when  their  constituents  pos- 
sess preservative  properties.  They  are  of  many  kinds,  but  may  be 
roughly  divided  as  they  are  mixed  with  water  or  with  oil.  Stains  are 
sometimes  prepared  by  adding  a  little  dry  pigment,  such  as  bismark 
brown,  to  shellac.  The  tints  presented  by  most  finished  hardwoods 
depend  upon  the  properties  of  the  stains  that  are  almost  invariably 
used  in  finishing  them. 

Avenarius  Carbolineum  is  an  antiseptic  wash  or  coating,  the  use  of 
which  has  been  attended  with  considerable  success,  particularly  in  the 
case  of  timbers  that,  after  having  been  treated  with  creosote  or  some 
other  preservative,  must  then  be  cut  or  fitted  upon  the  ground.  The 
manufacturers  recommend  the  use  of  at  least  two  coats  of  this  pro- 
prietary mixture,  which  is  said  to  consist  of  a  " coal-tar  distillate"  with 
zinc  chloride  and  other  preservatives.  It  should  be  applied  to  dry  and 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      389 

seasoned  wood.  Avenarius  Carbolineum  stains  clean  wood  a  nut-brown 
color.1 

Whitewash,  often  used  to  whiten  or  to  disinfect  woodwork,  is  pre- 
pared by  digesting  fresh  lime  in  water  until  the  lime  has  thoroughly 
slaked;  after  the  mixture  has  been  strained  into  a  clean  vessel,  it  is 
ready  for  use.  The  addition  of  glue,  salt,  linseed  oil,  and  some  other 
materials,  will  render  the  coating  more  permanent,  so  that  when  dry, 
it  will  not  rub  off  on  objects  that  come  into  contact  with  it. 

Kalsomine  is  a  mixture  of  fine  calcium  carbonate  of  the  grade  known 
as  Paris  white,  with  glue,  coloring  matter,  and  water.  Crude  chalk, 
that  is,  calcium  carbonate,  in  fine  powder,  is  agitated  in  water.  The 
coarsest  particles  settle  first,  while  those  that  are  finer  remain  longer  in 
suspension.  Paris  white  is  one  of  the  finest  of  the  grades  thus  separated. 
Whiting  is  another  grade. 

Most  " cold- water  paint"  contains  small  quantities  of  zinc  oxide, 
combined  with  larger  quantities  of  china  clay  and  casein.  As  used,  the 
latter  substance  dissolves  in  water  but  upon  drying  does  not  dissolve 
a  second  time.  "  Cold-water  paints,"  which  are  more  or  less  waterproof, 
are  comparable  with,  although  in  many  ways  superior  to,  whitewash 
and  kalsomine.  They  are  not  so  smooth  as  kalsomine  and  differ  from 
whitewash,  in  that  they  sometimes  become  mouldy  when  applied  in 
damp  places.  For  this  reason,  they  should  not  be  used  in  cellars. 

METHODS  OF  APPLICATION 

METHODS  USED  TO  APPLY  PAINTS.— The  methods 
employed  to  apply  paint  to  wood  have  a  fundamental  influence 
upon  the  durability  of  the  coatings.  The  paint  should  be 
thoroughly  mixed  until  it  reaches  an  even,  creamy  consistency. 
Portions  from  the  top  and  bottom  of  the  same  pail  have  less 
tendency  to  differ  from  one  another  if  the  paint  is  poured  from 
pail  to  pail,  back  and  forth,  just  before  using. 

Exposed  woodwork  should  be  painted  in  dry  weather,  when 
it  is  neither  dusty  nor  very  cold.  It  is  important  that  the  wood 
should  be  dry.  A  large  proportion  of  all  failures  is  due  to  the 
fact  that  paint  is  so  often  laid  upon  wood  that  contains  some 
moisture.  Paint  should  not  be  applied  when  the  weather  is 
foggy,  nor  should  it  be  applied  on  frost  crystals.  Dry  cold 
weather  prevents  paint  from  spreading  evenly.  Dust  and  grease 
also  interfere  with  results  in  proportion  to  their  quantities. 
Painting  should  always  begin  at  the  top  of  a  building  and  should 
then  progress  downward. 


1  Carbolineum  Wood  Preserving  Company,  New  York  City. 


390  ORGANIC  STRUCTURAL  MATERIALS 

Direct  sunlight,  particularly  during  the  summer,  is  detrimental. 
The  heat  of  the  sun  is  likely  to  cause  the  paint  to  form  in  drops 
or  " tears,"  while  its  reflected  light  will  influence  the  vision  and 
judgment  of  the  painters,  who  should  be  shifted  backward  and 
forward,  morning  and  afternoon,  with  the  intention  of  keeping 
them  in  the  shade  as  much  as  possible. 

The  treatment  required  by  new,  clean  wood  that  has  never 
been  painted,  differs  from  that  required  by  a  surface  that  has 
been  painted  before.  It  is  also  well  to  distinguish  between  fine- 
grained and  non-receptive  woods,  and  coarse-grained  and  recep- 
tive woods.  Such  distinctions  cause  details  to  vary;  but,  in  a 
general  way,  the  practice  of  painting  may  be  outlined  as  follows: 

A  surface  of  wood  that  is  to  be  painted  for  the  first  time  should 
be  planed,  sandpapered,  or  otherwise  cleaned.  The  knots  and 
other  pitch  wood  that  may  be  present  are  next  covered  with 
shellac;  and  if  large  knots,  or  other  imperfections,  exist,  ample 
squares  should  be  drawn  around  them  and  all  material  within 
the  squares  removed.  The  spaces  left  vacant  should  then  be 
filled  with  matched  squares  of  good  wood.  It  would  be  imprac- 
ticable to  attempt  to  fill  the  irregular  spaces  left  by  imperfections 
with  good  wood. 

The  first  or  priming  coat  is  now  applied,  after  which  all  nail 
holes,  and  other  depressions,  are  filled  with  white  lead  putty, 
which  may  be  tinted  so  as  to  accord  with  the  shade  of  the  sur- 
rounding surface.  Ample  time  is  allowed  for  the  work  to  dry, 
after  which  the  first  full  coat  of  paint  is  laid  on.  This  is  succeeded 
by  one  or  more  final  coats  as  desired.  It  is  important  that  every 
coat  should  be  thoroughly  dry  before  the  next  one  is  applied. 
Paint  shrinks  in  drying  and  every  coat  should  have  an  opportunity 
to  adjust  itself. 

Painting  upon  old  paint  is  to  be  distinguished  from  painting 
upon  new,  clean  wood.  Two  cases  present  themselves:  first, 
the  old  paint,  although  on  the  whole  firmly  and  solidly  attached 
to  the  wood,  must  be  removed  for  the  sake  of  appearance,  or 
because  it  is  worn  down  or  has  failed  in  places;  or,  second,  the 
old  paint  has  chalked,  cracked,  blistered,  or  become  loose. 

It  is  always  better  to  remove  old  paint;  yet,  if  the  paint 
adheres  well,  is  solid,  and  in  good  condition,  the  cost  of  removing 
it  is  not  warranted,  and  the  new  coats  may  then  be  laid  over  the 
existing  work,  as  already  noted.  As  distinct  from  this,  however, 
old  paint  that  has  chalked,  blistered,  or  otherwise  failed,  should 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      391 

invariably  be  removed,  as  it  may  be  by  scrapers,  steel  brushes, 
burning,  or  by  paint-removing  solutions.  After  the  old  paint  is 
removed  the  cleaned  surface  is  painted  as  though  for  the  first  time. 

A  failure  occurring  shortly  after  the  application  of  new  paint 
is  often  attributed  to  some  defect  in  that  paint;  whereas,  in  many 
instances,  it  is  the  priming  or  old  paint  that  is  at  fault.  Paint 
shrinks  in  drying,  and,  if  the  older  material  is  not  firmly  anchored, 
the  new  material  is  liable  to  pull  it  loose.  The  removal  of  old 
paint  is  very  costly,  yet  it  is  cheaper  to  remove  it  if  it  is  not  in  a 
fairly  good  condition. 

The  brush  should  be  held  at  right  angles  to  the  surface  so  that 
the  extremities  of  the  bristles  will  force  the  paint  into  the  pores 
of  the  wood.  The  strokes  should  be  applied  with  the  grain,  and 
should  be  drawn  out  as  far  as  possible  so  as  to  reduce  the  breaks 
in  the  lines  of  application.  Paint  is  not  distributed  as  evenly, 
nor  will  it  adhere  as  well,  unless  these  matters  are  attended  to. 

Paint  is  sometimes  applied  in  the  form  of  spray.  Thin  mix- 
tures, water  paints,  and  whitewash  have  been  successfully 
applied  over  large  surfaces  in  this  manner.  But,  as  distinct 
from  thin  mixtures,  the  attempts  that  have  been  made  to  apply 
thick  paints  by  means  of  spray  have  often  failed.  Thick  paints 
seem  to  require  a  different  kind  of  handling,  and  are  usually 
so  much  more  costly  that  less  waste  is  permissible.  A  machine 
for  spraying  paint  that  was  perfected  by  the  Pennsylvania  Rail- 
road Company  was  once  described  as  being  "  economical  as  a 
labor-saving  device  as  well  as  in  saving  of  paint  to  a  limited  ex- 
tent over  brush  work."  This  machine  is  still  in  service  and  giving 
satisfactory  results.1 

It  is  said  that  spray  work  compares  best  with  hand  work 
where  there  are  corners  or  complicated  surfaces.  As  against 
this,  spray  sometimes  encloses  air  which  interferes  with  solidity 
and  adhesion.  Experience  is  not  sufficient  to  enable  comparisons 
to  be  made  between  these  two  methods. 

A  general  specification  is  as  follows: 

Stir  the  paint  thoroughly.  Do  not  attempt  to  stir  through  the  bung' 
hole  of  the  package,  but  take  out  the  head  and  stir  with  a  stick  that  will 
reach  the  bottom.  Finally,  pour  the  paint  backward  and  forward  from 
pail  to  pail. 

1  July,  1915.  See  also  general  index  Engineering  News,  1890-1899, 
p.  174. 


392  ORGANIC  STRUCTURAL  MATERIALS 

After  a  storm  do  not  apply  paint  until  the  wood  has  had  time  to  dry. 
Never  apply  paint  in  damp,  foggy,  or  frosty  weather. 

It  is  often  advantageous  to  expose  surfaces  of  smooth  lumber  to  the 
weather  for  a  little  before  painting.  After  the  side  of  a  house  has  re- 
ceived rain  several  times,  the  grain  of  the  wood  will  rise  a  little;  and  then, 
after  it  has  become  dry,  the  paint  will  adhere  better. 

In  painting  begin  at  the  top  of  the  building  and  then  progress 
downwards. 

Knots  and  resinous  places  should  be  covered  with  shellac  varnish. 
After  which,  to  wood  that  has  not  been  painted  before,  the  compara- 
tively thin  priming  coat  should  be  applied.  The  priming  coat  may  be 
prepared  by  adding  raw  linseed  oil  to  some  of  the  paint  prepared  for 
the  later  coats. 

Seams  and  nail  holes  should  be  puttied  after  the  priming  has  been 
applied.  Every  coat  should  be  thoroughly  dry  before  the  coat  that 
follows  is  applied.  The  paint  should  be  rubbed  out  well  in  the  brush. 
It  should  not  be  permitted  to  flow  over  the  surface.  A  coat  that  is  not 
brushed  out  thin  will  blister  and  peel  away. 

Judgment  is  required  when  painting  a  house  that  has  already  been 
painted,  since  different  parts  of  such  a  surface  may  require  different 
treatment.  Cracked  and  loosened  paint  should  be  scraped  away.  Sur- 
faces that  are  entirely  bare  should  be  primed  as  already  noted.  Exist- 
ing paint  that  is  hard,  smooth,  and  firm  should  often  be  roughened  with 
coarse  sandpaper,  since  otherwise  the  new  coat  may  not  penetrate  and 
adhere  well  to  it. 

A  specification  for  somewhat  finer  work  is  as  follows : 1 

General  Conditions.  Bids. — The  owner  reserves  the  right  to  reject 
any  or  all  bids. 

No  Alterations. — No  interlineations,  erasures  or  alterations  of  any 
sort  will  be  allowed  unless  duly  noted  and  initialed  by  the  architect. 

Expert  Work. — All  work  must  be  executed  and  completed  according 
to  the  plans  and  specifications,  under  the  supervision  and  to  the  entire 
satisfaction  of  the  architect.  All  workmanship  must  be  expert  and 
thorough  in  every  respect. 

Extra  Work. — No  extra  work  will  be  accepted  or  paid  for  unless  or- 
dered in  writing  by  the  architect  before  it  is  done. 

Surfaces  Before  Beginning. — No  wood,  metal,  plaster,  or  other  work 
can  be  painted  or  varnished  until  inspected  and  approved  by  the  archi- 
tect. No  painting  or  varnishing  of  any  kind  is  to  be  done  on  wet  or 
damp  surfaces.  All  work  must  be  thoroughly  dry,  smooth  and  clean, 
and  all  scratches,  bruises,  cuts,  pencil  or  finger  marks  or  other  imperfec- 
tions must  be  obliterated  before  the  first  coat  is  applied.  Metal  sur- 

1  Slightly  abridged  from  specifications  prepared  by  Edward  Smith  & 
Company. 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      393 

faces  must  be  entirely  free  from  rust,  scale  and  oxidation  as  well  as  all 
other  defects. 

Woodwork  Before  Beginning. — All  woodwork  must  be  thoroughly 
seasoned,  the  surface  must  be  even  and  thoroughly  sandpapered  before 
the  first  coat  is  applied. 

Before  Beginning  Work. — The  painter  must  inspect  all  the  surfaces 
on  which  he  is  to  work,  before  beginning,  and  if  any  of  them  are  unsuit- 
able he  must  immediately  notify  the  architect.  He  must  not  begin 
until  the  surface  is  in  proper  condition. 

Sandpapering. — All  sandpapering  must  be  done  with  the  grain  and 
dusted  clean  before  applying  any  material  over  the  sanded  surface. 

Priming  Back  of  Woodwork. — Before  bringing  on  the  premises  or  im- 
mediately after,  the  back  of  all  fine  woodwork  must  be  thoroughly 
painted. 

Priming  on  Woodwork. — Dampness.  No  fine  woodwork  must  remain 
on  the  premises  over  night  without  receiving  the  first  priming  or  filling 
coat.  Unless  this  coat  is  applied  before  delivery  it  must  be  done  im- 
mediately after  (to  prevent  absorption  of  moisture  from  new  plaster 
or  masonry,  which  causes  warping, raising  of  the  grain  of  the  wood, etc.). 

Second  Coat  Priming  when  Necessary. — If  the  first  or  priming  coat  has 
been  removed  by  accident,  sandpapering  or  otherwise,  another  must  be 
applied  to  such  places  exactly  the  same  as  to  new  bare  surfaces.  No 
succeeding  coat  may  be  applied  until  all  such  defects  have  been  corrected 
in  the  first  or  priming  coat. 

Puttying. — All  nail  holes  and  other  depressions  must  be  filled  up  level 
and  smooth  with  white  lead  putty,  after  the  priming  or  filling  coat  has 
been  applied  and  is  thoroughly  dry.  If  the  first  coat  has  been  removed 
or  broken  another  priming  or  filling  coat  must  be  applied  before  puttying. 
All  putty  must  be  tinted  with  oil  colors  to  the  shade  of  the  surrounding 
surface  and  subject  to  the  approval  of  the  architect. 

Puttying  on  Filled  Woodwork. — No  steel  putty  knife  must  be  used  on 
filled  woodwork.  Only  a  hardwood  stick,  properly  shaped,  must  be 
used  on  such  surfaces. 

Knots  and  Sappy  Places. — All  knots,  sappy,  or  resinous  places,  if  they 
are  to  be  painted  or  enameled,  must  first  receive  one  coat  of  the  best 
shellac  varnish,  reduced  to  the  proper  consistency,  before  the  first  or 
priming  coat  is  applied. 

Each  Coat  to  be  Inspected. — Every  coat  must  be  thoroughly  dry  and 
approved  by  the  architect  before  the  next  is  applied.  No  coat  will  be 
counted  or  paid  for  without  the  approval  of  the  architect. 

No  "Oil  Rub"  on  Undercoats. — No  oil  of  any  kind  will  be  allowed  in 
rubbing  undercoats.  (A  portion  of  the  oil  will  remain  on  the  surface 
or  in  the  surface,  no  matter  how  carefully  it  is  cleaned,  and  this  is  sure 
to  injure  anything  applied  over  it.) 

Seals  and  Labels. — All  materials  to  be  used  must  be  on  the  premises 


394  ORGANIC  STRUCTURAL  MATERIALS 

when  ordered,  in  original  packages  with  seals  unbroken  and  labels  at- 
tached; and  must  be  approved  by  the  architect  before  they  are  used. 

No  Substitutes  on  Premises.  Thinners. — No  other  materials  of  a  simi- 
lar nature  will  be  allowed  on  the  premises  at  any  time.  No  turpentine 
or  other  thinners  may  be  used  except  as  per  printed  directions.  All 
varnishes,  enamels  and  other  materials  ready  for  use  must  be  used 
exactly  as  received  in  sealed  packages  from  the  makers. 

Invoices  for  All  Supplies. — Invoices  for  full  quantities  of  all  materials 
needed  for  the  work  must  be  shown  to  the  architect  and  approved  by 
him  before  the  work  is  paid  for. 

Quantities  Required. — At  least  one  gallon  of  material  must  be  used  for 
one  coat  on  five  hundred  square  feet  of  surface,  except  on  bare  wood. 
First  coat  on  bare  wood,  plaster  or  cement,  etc.,  requires  at  least  one 
gallon  of  material  to  each  three  hundred  square  feet  of  surface. 

Weights  per  Gallon. — White  lead  thinned  down  ready  for  use  weighs 
about  twenty  pounds  to  the  gallon.  Paste  wood  fillers  thinned  down 
ready  for  use  weigh  about  twelve  pounds  to  the  gallon. 

Temperatures  for  Varnishing  and  Enameling. — All  varnish  and  enamel 
coats  must  be  applied  and  dry  dust  free  between  60  degrees  and  80 
degrees  Fahrenheit.  (About  70  degrees  Fahrenheit  is  the  best  tempera- 
ture. Fifty  degrees  Fahrenheit,  or  even  lower,  is  not  always  injurious, 
but  the  danger  increases  with  the  cold  and  the  risk  of  poor  results  at 
low  temperatures  should  be  clearly  defined  and  the  responsibility  for 
them  placed  beforehand.  The  danger  continues  until  the  coat  is  well 
out  of  "tack.") 

Materials  Required. — All  varnishes,  enamels,  japans,  dryers,  fillers, 
stains,  colors  in  oil,  tinting  colors,  graining  colors  and  similar  materials 
must  be  those  manufactured  by —  — .  All  linseed  oil, 

white  lead,  white  zinc  and  turpentine  must  be  absolutely  pure  and  of 
the  best  qualities. 

Danger. — Oil,  lead,  zinc  and  turpentine  are  exceedingly  important, 
and  great  care  and  vigilance  are  required  to  prevent  the  use  of  inferior 
or  adulterated  qualities  of  these  articles. 

Covering  Capacity  of  Paints. — Paints  vary  in  covering  capacity. 
Results  are  influenced  by  the  properties  of  the  paints  themselves, 
by  the  condition  of  the  wood  to  which  the  paints  are  applied,  and 
by  the  methods  and  personality  of  the  painter.  It  is  well  to 
allow  one  gallon  of  thin,  priming  paint  for  every  two  hundred 
square  feet  of  surface  of  open-grained  wood,  although  it  can  be 
made  to  cover  twice  that  amount,  particularly  if  applied  to  close- 
grained  wood.  One  gallon  of  ordinary  paint  should  cover  from 
three  hundred  square  feet  to  five  hundred  square  feet  of  plain 
surface  that  has  already  been  primed.  There  are  many  excep- 
tions to  these  general  figures. 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS     395 

A  certain  amount  of  paint  may  be  spread  so  that  it  will  cover 
a  very  large  surface;  but,  in  this  case,  the  coat  is  likely  to  be  too 
thin.  On  the  other  hand,  a  coat  of  paint  should  not  be  too  thick 
because  a  thick  coat  of  paint  is  liable  to  peel.  As  a  matter  of 
fact,  the  thickest  coat  of  paint  that  may  be  applied  without 
danger  of  peeling  is  actually  very  thin,  and  the  saving  of  a  small 
quantity  of  material  is  less  important  than  the  length  of  time 
during  which  the  coat  can  be  made  to  last.  With  charges  for 
labor  as  they  are,  paint  should  not  only  be  selected  with  the  idea 
of  obtaining  the  longest  possible  term  of  service,  but  it  should  be 
applied  with  that  object  first  in  view. 

Time  Required  to  Apply  Paint. — The  time  required  to  apply 
paint  is  influenced  by  the  paint  itself,  the  surface  that  is  to  be 
covered,  and  the  habits  of  the  painter.  An  intricate  surface 
requires  longer  than  one  that  is  plain  and  flat.  It  takes  longer 
to  apply  paint  overhead  than  to  apply  it  on  a  level  with  the  body; 
and  it  is  easier  to  work  from  a  scaffold  than  from  a  ladder. 
Fine  interiors  call  for  more  attention  than  ordinary  exteriors. 

Inquiries  addressed  to  several  railway  companies  brought  replies  indi- 
cating that  a  good  workman  should  cover  from  fourteen  hundred  square 
feet  to  two  thousand  square  feet  of  plain,  flat,  primed  surface  in  a  day 
of  eight  hours.  Priming  requires  longer.  At  least  ten  per  cent,  of  the 
time  devoted  to  painting  should  be  allowed  for  cleaning,  sandpapering, 
puttying,  and  mixing.  These  figures,  although  based  upon  actual  work, 
cannot  be  applied  too  literally,  particularly  to  small  pieces  of  work,  or 
when  fine  surfaces  are  to  be  prepared. 

Durability  of  Paints. — This  varies  greatly  with  materials, 
methods  of  application,  use,  and  exposure.  The  need  of  judgment 
and  integrity  on  the  part  of  the  painter  is  very  great.  Sunlight 
and  rain  are  the  common  enemies  of  paint.  White  lead  will  last  a 
century  under  cover,  but  fail  in  a  few  years  when  out  of  doors. 
Impure  air,  and  moist  gases  such  as  come  from  locomotives, 
destroy  paints  more  or  less  rapidly.  The  life  of  a  coat  of  paint 
cannot  be  predicted,  even  when  it  has  received  the  most  intelli- 
gent attention.  When  the  coat  fails  it  must  be  renewed. 

THE  APPLICATION  OF  VARNISH.— Varnish  may  be  used 
as  paint  is  used,  or  it  may  serve  in  connection  with  the  more 
complicated  surfacing  included  within  the  meaning  of  the  word 
polish.  Although  varnish  is  used  in  polishing  wood,  a  varnished 
surface  is  to  be  distinguished  from  a  polished  surface. 


396  ORGANIC  STRUCTURAL  MATERIALS 

Many  of  the  details  connected  with  wood  finishing  in  which 
varnishes  are  employed  are  specially  associated  with  certain  kinds 
of  work.  The  protection  of  a  porch  or  mast  differs  from  the  re- 
quirements of  a  piano  or  a  coach.  Appearance  is  of  much  im- 
portance with  most  woodwork  upon  which  varnish  is  employed. 

The  appearance  of  cabinet  woods  is  influenced  by  fashion,  and 
fashion  changes  so  that  the  same  wood  is  often  finished  in  differ- 
ent ways  at  different  times,  even  although  the  wood  is  to  be  em- 
ployed for  the  same  purpose.  Mahogany  may 'thus  be  finished 
with  a  bright  luster;  or  it  may  be  dull.  Sometimes  it  is  of  a  rich 
mahogany  red,  and  at  others  it  is  yellow  or  dark  brown.  Oak 
is  finished  in  many  colors  such  as  natural  yellows,  grays,  greens, 
browns,  and  blacks.  These  results  are  obtained  by  the  use  of 
stains,  varnishes,  wax,  and  other  materials,  and  by  differences  in 
methods  of  application. 

The  principal  difference  between  a  plain  varnished  surface 
and  one  that  is  polished  is  due  to  a  distinction  between  the 
amounts  and  kinds  of  labor  that  are  employed. 

It  will  be  remembered  that  woods  are  divided  according  as 
they  are  porous,  like  mahogany,  or  close  grained,  like  maple. 
All  woods  must  be  dry,  and  all  must  be  brought  to  a  smooth, 
clean,  even  finish  before  they  are  treated  in  any  way. 

Plain  Varnished  Surfaces. — Varnish  may  be  used  as  paint  is 
used.  It  may  be  applied  directly  to  filled  or  unfilled  woods. 
The  varnish  need  not  be  rubbed  down  and  polished. 

Filler  may  be  used  upon  a  surface  that  is  to  be  varnished. 
The  procedure  resembles  that  associated  with  the  preparation  of 
surfaces  for  polishing,  but  is  distinct  in  that,  as  stated,  the  var- 
nish is  not  rubbed  down  and  polished  after  it  has  been  applied. 

Varnish  is  often  applied  to  otherwise  unfilled  wood,  in  which 
case  the  varnish  itself  acts  as  a  filler.1  The  very  durable  and 

1  From  correspondence  with  William  H.  Oliver:  "In  years  past  many  of 
the  wood  polishers  made  their  own  filler,  but  it  was  even  then  thought  that 
the  better  way  to  treat  hard  woods  was  to  give  them  all  the  oil  or  varnish 
they  would  take.  Each  coat  was  sandpapered  to  the  surface  of  the  wood, 
and  it  was  necessary  to  repeat  the  coats  and  the  sand  papering  until  the 
pores  were  thoroughly  filled.  Afterward,  the  necessary  coats  to  preserve 
the  wood  and  permit  polishing  and  rubbing  were  added.  I  have  always 
been  of  the  opinion  that  if  this  course  was  generally  followed  at  the  present 
time  better  results  would  be  obtained.  I  hold  that  in  this  way  not  only 
are  pores  filled,  but  the  wood  is  better  protected.  It  seems  to  me  that 
wood  thus  treated  is  brighter  and  clearer  than  when  ordinary  paste  filler 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS      397 

elastic  mixture  known  as  spar  varnish  is  often  used  in  this  way 
upon  masts,  doors,  porches  and  other  exposed  woodwork. 
When  thus  used,  applications  of  this  varnish  are  repeated  until  a 
sufficient  body  has  been  built  upon  the  wood.  A  coat  prepared 
in  this  way  will  not  separate  from  the  wood  even  when  exposed 
to  the  most  severe  weather1. 

Polished  Surfaces. — Although  the  engineer  has  less  to  do  with 
polishing  than  with  painting,  the  subject  deserves  attention  suffi- 
cient to  enable  him  to  specify  such  fundamental  factors  as  are 
necessary  to  secure  the  results  he  desires. 

Close-grained  woods  are  first  treated  with  appropriate  fillers. 
The  unabsorbed  portions  of  the  fillers  are  rubbed  away  with  rags 
or  excelsior  as  soon  as  they  have  had  time  to  dry,  the  movement 
being  across  the  grain.  The  cracks  and  nail  holes  are  next 
puttied;  the  surface  is  sandpapered,  andj  if  a  stain  is  desired,  it 
is  applied  at  this  stage.  Afterward,  a  thin  coat  of  light-tinted 
or  orange  shellac  is  brushed  on  and  the  surface  is  again  sand- 
papered. A  coat  of  varnish  is  spread  evenly  over  the  surface, 
and  is  allowed  to  dry  for  two  or  three  days.  The  surface  is 
then  attacked  by  powdered  pumice,  with  oil  or  water,  and  rubbed 
with  the  grain,  until,  to  all  appearances,  it  is  removed.  Felt  or 
haircloth  is  used  in  this  operation. 

Other  coats  of  varnish  are  added  in  the  same  manner.  Each 
one  is  allowed  to  dry  thoroughly,  and  is  then  rubbed  down  to  a 
smooth  surface  with  powdered  pumice.  The  polish  is  brought 
out  by  rubbing  the  last  coat  with  rotten-stone  instead  of  with 
pumice. 

Details  vary  with  fashions,  finishers,  and  the  necessities  of  the 
wood.  Very  smooth  surfaces,  such  as  those  seen  on  pianos,  are 
obtained  by  finally  rubbing  the  surface  with  the  palm  of  the 
hand.  Oil  and  pumice  give  what  is  known  as  " oil-finish," 
while  water  and  pumice  give  what  is  known  as  "  water-finish." 
The  appearance  and  wearing  qualities  of  polished  surfaces  vary 
greatly.  Some  surfaces  appear  to  be  thick  and  glassy,  while 
others  are  more  solid,  and  subdued. 

is  employed,  and  that  it  is  better,  also,  for  the  life  of  the  wood  than  a 
material  is  which  simply  coats  the  surface,  but  has  no  real  penetrating 
power.  ...  I  have  thought  for  some  time  that  the  filler  generally  used 
not  only  darkens  light  wood  in  time,  but  that  it  has  some  chemical  action 
upon  the  varnish  or  shellac ;  but  whether  this  is  so  I  must  leave  for  others 
to  determine." 

1  See  "Technology  of  Paint  and  Varnish,"  Sabin  (First  Edition,  p.  299). 


398  ORGANIC  STRUCTURAL  MATERIALS 

In  the  best  work,  the  varnish  penetrates  deep  into  the  wood. 
Such  a  surface  is  " case-hardened;"  it  wears  evenly  because  the 
wood  elements  of  the  surface  are  filled  and  rendered  compact  by 
the  tough  hard  varnish.  In  this  case  very  little  varnish  remains 
on  the  outside  of  the  wood,  and,  with  ordinary  use,  the  appear- 
ance of  such  a  surface  may  improve  with  age.  Where  the  work 
is  inferior  very  little  labor  is  bestowed  upon  the  varnish.  The 
superfluous  varnish  is  not  rubbed  away,  and  no  attempt  is  made 
to  work  the  first  coats  into  the  fabric  of  the  wood.  In  this  case 
most  of  the  varnish  remains  upon  the  surface  of  the  wood; 
such  a  surface  may  be  more  or  less  attractive  when  new,  but 
shortly  scratches,  chips  and  wears  away. 

As  already  stated,  the  appearance  of  a  surface  is  influenced 
by  its  color  as  well  as  by  its  texture.  The  tints  presented  by 
most  finished  hardwoods  are  secured  by  the  use  of  stains,  and, 
in  the  best  work,  these  stains  are  selected  so  as  to  accord  with 
and  emphasize  such  beauty  as  is  due  to  the  cellular  structure  or 
" grain"  of  the  wood. 

It  is  fundamental  that  stains  shall  be  spread  evenly.  This  is 
often  hard  to  accomplish  because  different  parts  of  a  piece  of 
wood  are  liable  to  vary  in  their  density  and  ability  to  absorb. 
It  is  often  necessary  to  retouch  the  wood  here  and  there  so  as 
to  offset  such  differences.  Many  stains  darken  with  age,  and  it 
is  usually  easier  to  correct  a  tint  that  is  too  light  than  to  correct 
one  that  is  too  dark. 

The  summary  that  follows  was  prepared  by  the  foreman  of  a 
noted  firm  of  cabinet  makers. 

"In  order  to  secure  a  good  piece  of  work:  (1)  Fill  with  the  best 
filler;  (2)  color  if  necessary;  (3)  apply  a  thin  coat  of  the  best  shellac; 
(4)  apply  three  coats  of  the  best  varnish — allow  each  coat  to  dry  for 
two  days  at  least;  (5)  rub  down  each  coat  until  a  smooth  surface  is  ob- 
tained with  pumice  stone  and  felt — allow  one  day  to  dry  perfectly,  then 
finish  with  rotten-stone,  and,  if  a  very  fine  surface  is  required,  rub  with 
the  palm  of  the  hand;  (6)  clean  entire  surface  of  work  with  a  mixture 
of  raw  linseed  oil  and  turpentine  (equal  parts),  then  take  cheesecloth 
and  rub  perfectly  dry.  To  obtain  the  best  of  work,  it  is  absolutely 
necessary  that  the  woodwork  be  perfectly  smooth  and  well  filled  before 
the  work  is  varnished." 

Enameled  Surfaces. — Varnish  or  enamel  paint  has  been  de- 
scribed as  a  mixture  of  varnish  and  pigment.  In  such  a  paint, 
.varnish  takes  the  place  of  the  usual  linseed  oil,  with  the  result 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS     399 

that  the  paint,  although  more  costly,  is  harder  and  more  durable. 
A  little  varnish  is  often  added  to  ordinary  oil  paint,  the  luster  of 
which  is  thus  increased.  Enamel  paint  may  be  applied  on  wood 
or  metal  either  indoors  or  out  of  doors.  The  paint  may  be  laid 
on  as  described  in  the  preparation  of  "  plain  varnished  sur- 
faces;" or,  a  real  enamel  may  be  built  up  by  methods  described 
in  connection  with  "  polished  surfaces." 

In  the  latter  case,  the  wood,  having  been  prepared  and  primed  in  the 
ordinary  manner,  is  treated  to  two  or  three  coats  of  flat  white  lead  paint 
each  one  of  which  is  permitted  to  dry  thoroughly,  and  is  then  lightly 
sandpapered.  One  coat  of  zinc  white  paint  is  then  applied,  and,  after 
it  has  become  dry,  is  also  sandpapered.  The  base  thus  prepared  is 
covered  with  a  coat  of  enamel  paint  which  is  later  rubbed  down  with 
pumice  stone  and  water,  on  felt,  to  a  uniform  and  level  surface.  This  is 
carefully  washed  free  of  all  pumice  with  cold  water,  and  is  then  wiped 
dry  with  chamois.  One  or  two  other  coats  of  enamel  paint  are  then 
applied  in  the  same  way.  A  surface  built  up  in  this  manner  is  very 
beautiful,  smooth,  easily  cleaned,  neutral,  and  permanent.  A  base  of 
birch  or  cherry  thus  enameled  is  usually  more  costly  than  a  base  of 
quartered  oak  or  even  mahogany  that  has  been  polished.  The  differ- 
ence in  cost  is  due  to  the  excessive  amount  of  labor  required  to  build 
up  good  enamel. 

Varnish  is  sometimes  replaced  by  wax  which  causes  an  old, 
or  " antique"  appearance.  The  wood  is  first  leveled,  sand- 
papered, cleansed,  or  otherwise  prepared;  and  is  then  stained  and 
treated  with  shellac,  varnish,  or  with  both  of  these  mixtures. 
Wax  is  applied  and  time  is  allowed  for  it  to  dry.  The  whole 
surface  is  then  carefully  rubbed  with  cheesecloth  or  some  similar 
material.  The  shellac  and  varnish  are  sometimes  omitted. 
Appearance  is  governed  by  these  and  other  details. 

MISCELLANEOUS. — Ships,  cars,  coaches  and  some  other 
constructions,  require  special  methods  that  are  distinct  from 
those  by  which  ordinary  woods  are  commonly  protected. 

Ship  Painting. — Ordinary  wooden  hulls  are  protected  much  as 
wooden  houses  are  protected.  But,  as  distinct  from  these,  many 
pleasure  boats  and  war  ships  require  special  treatment.  The 
vessels  now  referred  to  are  those  that  are  painted  so  frequently 
that  excessively  thick  coats  of  paint  would  accumulate  if  ordinary 
methods  were  held  to.  In  such  cases,  white  lead  is  mixed  with 
turpentine  instead  of  with  linseed  oil.  This  produces  a  thin 
white  coat  that  looks  well  for  the  time  being,  but  that  soon 


400  ORGANIC  STRUCTURAL  MATERIALS 

chalks,  and  can  then  be  brushed  away.     Special  paints  have  been 
designed  to  protect  ship  bottoms. 

Coach  Painting. — In  this  case,  brilliant  polishes  have  to  resist 
severe  exposure  and  constant  washings.  The  influence  of  heat, 
cold,  wet,  and  abrasion  must  be  withstood.  Coach  painting 
occupies  a  field  by  itself. 

Car  Painting. — Methods  employed  in  the  shops  of  the  Pullman 
Company  are  as  follows:1 
System  for  Painting  Exteriors  of  Cars. 

1.  After  the  exterior  of  the  car  has  been  properly  sanded  and  made 
ready  for  painting,  dust  off  the  car  with  a  painter's  duster,  and  then 
apply  the  priming  coat,  which  should  be  well  brushed  into  wood  and 
allowed  to  dry  three  days. 

2.  Apply  the  filling  coat,  or  the  second  lead. 

3.  Putty  all  nail  holes  and  bruises  the  next  day,  and  then  allow  the 
second  lead  and  putty  to  dry  two  days. 

4.  Apply  three  coats  of  surfacer,  one  coat  a  day. 

6.  Rub  down  to  a  smooth  surface  with  lump  pumice  stone  or  Eureka 
rubbing  stone,  and  then  sandpaper. 

6.  Apply  the  color  course  of  two  or  three  coats,  one  a  day. 

7.  Ornament  and  letter  and  then  apply  three  coats  of  Railway  Body 
Varnish,  allowing  a  day  between  coats  for  drying. 

System  for  Finishing  Interiors  of  Cars. 

1.  After  the  finish  is  properly  cleaned  and  sandpapered,  fill  the  pores 
with  a  wood  filler  and  allow  it  to  dry  over  night. 

2.  Sandpaper  with  No.  0  sandpaper;  shellac  and  varnish  it  the  next 
day  and  allow  it  to  dry  one  day. 

3.  Apply  the  second  coat  of  varnish  and  let  dry  one  day. 

4.  Apply  the  third  coat  of  varnish,  letting  it  stand  to  dry  two  days 
before  rubbing. 

5.  Rub   with   pumice   stone   and  water  and  let  dry  one  day  before 
polishing. 

6.  Polish  with  rotten  stone  and  oil. 

OTHER  COATINGS  APPLIED  TO  SURFACES  OF  WOOD. 

— Metals  are  sometimes  used  to  beautify  woods  and  to  protect 
them  from  decay;  but  they,  as  well  as  paints,  seal  up  moisture 
that  may  be  present,  and  should  not  be  used  save  with  woods 
that  are  quite  dry  and  well  seasoned.  Wooden  pillars  are  some- 
times enclosed  by  metals,  as  are  the  bottoms  of  wooden  ships. 

The  bottoms  of  posts  and  poles  are  sometimes  charred.     As 
has  been  explained  elsewhere,  high  heat  sterilizes  the  wood  and 

1  In  force  January,  1912. 


OILS  PAINTS  VARNISHES  AND  OTHER  COATINGS     401 

thus  increases  its  durability;  but,  besides  this,  the  coat  of  prac- 
tically inert  charcoal  is  also  beneficial.1  Charring  can  be  local- 
ized, and  is  often  practised  with  the  ends  of  green  posts  that  would 
otherwise  rot  rapidly  near  the  surface  of  the  soil.  The  upper 
portion  of  such  pieces  then  have  time  to  season  naturally. 


FIG.  79. — Failure  of  car  post  due  to  application  of  paint  upon  imperfectly 

seasoned  wood. 

Attention  has  been  called  to  the  fact  that  external  coatings 
may  assist  wood  by  offering  resistance  to  animal  woodborers, 
fire,  an  abrasion,  as  well  as  to  rot.  Asbestos  paint,  in  which 
water-glass  is  the  vehicle  and  powdered  asbestos  the  pigment, 
is  thus  used  as  a  fire  retardant.  The  water-glass  fuses  easily, 

^ee  chapter,  "Preservative  Methods  Internal  Treatment." 


402  ORGANIC  STRUCTURAL  MATERIALS 

and,  when  fused,  flows  over  the  burning  surface,  and  for  the 
time  cuts  off  the  volatile  gases  that  cause  flame.1 

It  will  be  remembered  that  so-called  " fireproof  paints" 
retard,  but  they  do  not  prevent,  burning.  Some  paints  of  this 
class  act  upon  woods  when  in  certain  positions  by  lessening  the 
ease  with  which  such  woods  might  take  fire  from  small  flames. 
It  will  also  be  remembered  that  wood  covered  with  tin  has  re- 
sisted fire  in  conflagrations  when  solid  metal  has  buckled  and 
failed. 

THE  PREPARATION  OF  WOODS  TO  RECEIVE  PAINTS,  VAR- 
NISHES AND  OTHER  COATINGS 

Coatings  protect  from  outside  conditions  only.  They  do  not 
protect  from  inside  conditions,  and  may  even  do  harm  if  mois- 
ture or  impurities  are  not  removed  before  they  are  applied. 
It  is  then  much  the  same  as  when  imperfectly  cured  fruits  are 
sealed  in  cans.  Decay  can  go  forward  within  a  can,  and  it 
can  also  go  forward  within  a  coat  of  paint.  The  condition 
known  as  " dry-rot"  is  observed  where  imperfectly  cured  woods 
are  thus  enclosed  by  paints  or  other  coatings. 


1  See  chapter,  "Failure  of  Wood  Because  of  Fire." 


CHAPTER  XVI 

ADHESIVES.     CATTLE  GLUES.     FISH  GLUES.     SELECTION, 
TESTING  AND  APPLICATION  OF  GLUES 

Glue  is  prepared  from  parts  of  animals.  It  is  used  to  join 
pieces  of  wood  together;  and  is  also  used  in  printers'  rollers,  emery 
wheels,  book  bindings,  artificial  leather,  and  for  sizing  cloths 
and  papers.  Kalsomine  is  a  mixture  of  glue  and  Paris  white. 
About  ninety  million  pounds  of  glue  are  produced  in  the  United 
States  alone  every  year. 

True  glue  is  impure  gelatine.  Gelatinous  pastes  resembling 
jellies  of  weak  glue,  are  formed  by  some  vegetable  products;  but 
these  pastes  differ  from  true  glues  in  that  they  do  not  resume 
their  original  forms  when  they  become  dry,  neither  do  the  dried 
products  dissolve  satisfactorily  the  second  time.  A  jelly  of  true 
glue  will  dry  into  a  substance  that  is  practically  identical  with 
the  original,  and  this  substance  will  dissolve  and  then  gelatinize 
a  second  time. 

Glues  and  gelatines  should  be  distinguished  from  one  another. 
Both  substances  are  obtained  from  the  same  sources,  but  the 
former  is  less  definite  in  composition  than  the  latter.  Pure 
gelatine  may  be  described  as  the  essential  part  of  glue,  while 
glue  may  be  described  as  impure  gelatine.  Ordinary  carpenter's 
glue  contains  about  fifty  per  cent,  of  pure  gelatine  which  may 
be  separated  from  the  glue  by  laboratory  treatment.  As  a 
matter  of  fact,  commercial  gelatine  or  isinglass,  as  distinct  from 
pure  gelatine,  is  usually  prepared  directly  from  special  sources. 
The  line  of  separation  between  some  glues  and  some  gelatines 
is  hard  to  define. 


REFERENCES. — "Glue,  Gelatine,  Isinglass,  Cements,  and  Pastes,"  Dawid- 
owsky  (Sampson  Low,  Marston,  Searle  &  Rivington,  London,  1884);  "Glue 
and  Glue  Testing,"  Rideal  (Scott,  Greenwood  &  Company,  London,  1900); 
''Glues  and  Gelatine,"  Fernbach  (Van  Nostrand  Company,  1907);  Files  of 
Scientific  American,  Woodcraft,  etc.  Assistance  has  also  been  received  from 
Messrs.  Armour  &  Company,  the  American  Glue  Company,  the  Russia 
Cement  Company,  the  Studebaker  Corporation,  Schmitt  Brothers,  The 
Flint  &  Horner  Company,  and  other  manufacturers  and  users  of  glue. 

403 


404  ORGANIC  STRUCTURAL  MATERIALS 

Gelatine,  which  is  nearly  colorless,  nearly  tasteless,  and  almost 
without  odor,  is  used  in  medicines,  photography,  confections, 
and  as  an  agent  in  clarifying  liquids.  As  distinct  from  gelatine, 
glue  possesses  color,  taste,  and  odor;  but,  because  glue  is  used 
primarily  as  an  adhesive,  these  properties  do  not  diminish  its 
value. 

The  exact  chemical  composition  of  pure  gelatine  has  not  yet  been 
deduced,  but  analyses  show  that  the  ultimate  composition  is  about  as 
follows:  Carbon,  50  per  cent.;  oxygen,  25  per  cent.;  nitrogen,  18  per 
cent.;  hydrogen,  6.9  per  cent.;  sulphur,  etc.,  traces.  Rideal  and  Fern- 
bach1  call  attention  to  the  complex  composition  of  gelatine.  Beside 
albumoses  and  peptones,  several  varieties  of  chondrin,  mucin,  and  other 
chemical  substances  may  be  present. 

Glues  and  gelatines  are  derived  from  cattle  and  from  fishes. 
Cattle  glues  are  more  largely  used,  and  are  usually  intended 
unless  fish  glues  are  particularly  specified.  It  should  be  noted 
that  glues  and  gelatines  do  not  exist  as  such  in  the  tissues  from 
which  they  are  drawn,  but  that  they  are  formed  by  the  action 
of  heat  and  water  upon  certain  nitrogenous  substances  that  are 
contained  in,  or  that  are  a  part  of,  these  tissues.  The  fact  that 
certain  animal  tissues  can  be  made  to  yield  certain  products 
through  the  instrumentality  of  heat  and  water  is  known,  but 
the  nature  of  the  changes  which  brings  about  these  results  is 
not  known. 

CATTLE  GLUES 

SOURCES. — The  sources  of  cattle  glue  may  be  separated  into 
three  groups  as  follows: 

Hidestock  includes  scraps  and  cuttings  from  tanneries,  to- 
gether with  sinews,  and  pieces  known  as  fleshings  that  are 
shaved  from  inner  surfaces  of  skins.  Hidestocks  from  horned 
cattle,  sheep,  rabbits,  and  other  animals,  yield  glues  that  differ 
from  one  another  in  minor  properties.  The  second  group  in- 
cludes bonestock,  that  is,  the  bones  of  certain  animals  as  horned 
cattle;  and  footstock  includes  the  hoofs  of  horned  cattle,  pigs, 
and  some  other  animals. 

MANUFACTURE.— Clean  hidestock  is  digested  or  "limed" 
in  some  weak  alkali,  as  lime  water,  that  attacks  the  fats,  loosens 
the  hair,  and  softens  the  tissues  that  contain  the  glue.  After 

1  See  text  by  these  authors. 


CATTLE  AND  FISH  GLUES  405 

a  sufficient  time  the  alkali  and  impurities  are  removed  by  wash- 
ing, and  the  soft  and  swollen  residues  are  boiled  in  water.  Each 
charge  of  stock  is  boiled  several  times,  but  the  solutions  are  kept 
separate  from  one  another  since  each  one  yields  a  different  grade 
of  glue.  The  best  glue  is  that  which  comes  from  the  first  boiling. 
Next,  the  glue  solutions  are  poured  into  moulds  and  per- 
mitted to  cool,  and  the  blocks  of  jelly  that  result  are  cut  into 
slices.  The  slices  are  arranged  on  nets  of  twine  or  wire  designed 
to  facilitate  drying,  and  are  dried  in  the  open,  or  in  cabinets 
where  conditions  may  be  more  easily  controlled.  It  is  not  easy 
to  dry  these  jellies  satisfactorily.  Results  are  much  influenced 
by  temperature  and  humidity.  Some  difficulties  are  expressed 
in  the  following  quotation:1  "The  glue-maker  has  all  sorts  of 
troubles.  His  best  jelly  may  be  hurt  or  ruined  by  the  weather 
or  by  unwise  liming  or  cooking.  Anything  will  affect  his  glue 
and,  for  this  reason,  no  two  boilings  can  be  alike." 

Bonestock. — Clean  bones  are  treated  in  either  of  two  ways:  First, 
They  are  boiled  directly  without  prior  treatment;  or  second,  they  are 
digested  in  weak  acids  that  dissolve  the  lime  and  other  salts.  The  acids 
are  then  neutralized  and  the  cleansed  residues  are  boiled  in  water.  The 
solutions  obtained  from  the  bones  of  different  species  of  animals  yield 
different  grades  of  glue. 

Footstock. — This  is  washed  and  boiled  without  preliminary  treatment. 
The  solutions  obtained  by  boiling  the  hoofs  of  different  kinds  of  animals 
are  kept  separate  from  one  another. 

PROPERTIES. — Cattle  glues  are  hard  and  tough.  The  taste 
and  odor  are  characteristic,  and  the  colors  range  through  a  series 
of  more  or  less  translucent  grays  and  browns.  Cattle  glues 
soften  and  swell,  but  do  not  dissolve,  when  treated  with  cold  water. 
They  dissolve  completely  in  hot  water,  and  the  resulting  solutions 
eventually  stiffen  into  jellies  and  pass  into  the  original  dry  form 
of  the  glue.  Cattle  glue  can  be  dissolved  and  dried  many  times; 
but  each  operation  weakens  the  power  of  the  glue,  and  a  point 
is  finally  reached  where  the  glue  remains  permanently  in  solution. 
Cattle  glue  also  dissolves  in  acetic  acid. 

Many  grades  of  glue  are  manufactured  in  the  United  States. 
Some  are  based  upon  differences  that  exist  between  the  materials 
from  which  the  glues  are  made;  and  others  are  due  to  differences 
of  manufacture.  Every  maker  produces  a  series  peculiar  to  him- 
self, and  the  properties  of  the  grades  that  go  to  make  up  this 

1  "A  Pot  of  Glue,"  Milligan  and  Higgins  Company. 


406 


ORGANIC  STRUCTURAL  MATERIALS 


series  sometimes  change  from  day  to  day  with  the  weather,  or 
from  other  causes. 

Glues  differ  in  form  as  well  as  in  character.  Foreign  glues  are 
usually  sold  in  square  or  oblong  cakes,  each  of  which  is  branded 
with  the  mark  of  the  manufacturer.  As  distinct  from  this, 
glues  made  in  the  United  States  are  usually  broken  into  frag- 


FIG.  80. — Typical  forms  of  domestic  and  foreign  cattle  glues.  (Much 
reduced.)  The  cakes  of  foreign  glue  at  the  top  of  the  picture  show  the 
brands  of  manufacturers. 

ments,  known  as  "  flakes,"  and  these  are  often  ground  into  powder. 
There  are  also  noodle,  strip,  ribbon,  and  some  other  forms. 

Two  reasons  are  given  for  the  local  custom  of  breaking  the  cakes  of 
glue  into  fragments:  The  first  is,  that  inequalities  can  be  counteracted 
by  judicious  blending;  and  the  second  is,  that  it  is  easier  for  consumers 
to  work  with  glues  that  have  been  broken  for  them.  The  viewpoint  of 
the  manufacturer  has  been  expressed  as  follows:1  "The  boilings  of  glue 

1<4A  Pot  of  Glue,"  Milligan  and  Higgins  Company. 


CATTLE  AND  FISH  GLUES  407 

run  from  three  to  ten  barrels,  and,  as  said  above,  vary.  But  take  ten 
boilings,  say  fifty  barrels,  and  grind  them  together  we  can  then  give  a 
man  a  sample  behind  which  we  can  be  sure  of  every  pound;  and  we  can 
make  successive  lots  to  match  that  one.  It  means  uniformity,  conven- 
ience, and  economy."  It  is  true  that  cattle  glues  must  be  broken  be- 
fore they  are  dissolved  in  water,  but  the  convenience  of  having  them 
broken  by  the  manufacturer  is  sometimes  offset  by  the  greater  ease  with 
which  fragments  or  powders  can  be  mixed  or  even  adulterated  by  un- 
scrupulous dealers. 

Comparison  of  Foreign  and  Domestic  Glues. — Foreign  manu- 
facturers seldom  employ  as  many  kinds  of  stock,  or  produce  as 
many  grades  of  glue,  as  those  who  manufacture  in  this  country. 
The  foreign  custom  of  presenting  glues  in  unbroken  or  branded 
cakes  makes  it  easier  for  consumers  to  identify  foreign  glues. 
Foreign  makers  give  much  attention  to  appearance;  labor  condi- 
tions are  such  that  stock  can  be  selected  with  greater  care  than 
in  this  country,  and  glue  solutions  are  often  clarified  to  such  an 
extent  that  foreign  glues  are  nearly,  if  not  quite,  translucent. 

Aside  from  form  and  appearance,  it  is  probable  that  the  domes- 
tic product  as  a  whole,  is  quite  equal  to  the  foreign  product 
as  a  whole.  It  is  true  that  the  large  number  of  grades  of  glue 
manufactured  in  the  United  States  causes  some  confusion,  since 
customers,  who  are  often  unable  to  tell  one  kind  from  another, 
must  depend  more  largely  upon  those  from  whom  they  buy. 
But,  on  the  other  hand,  the  fact  that  there  are  so  many  kinds  of 
glue  is  a  source  of  strength,  because  it  makes  it  possible  for 
Americans  to  fill  almost  every  need. 

Special  Forms. — Cattle  glue  is  sometimes  dissolved  in  acetic 
acid  and  then  sold  in  the  form  of  a  liquid.  Cattle  glue  may  be 
rendered  flexible  by  mixing  it  with  glycerine  and  water,  to  which 
molasses,  or  sugar  in  some  other  form,  is  usually  added.  The 
proportions  of  ingredients  vary  according  to  the  results  desired; 
a  mixture  composed  of  one-half  glycerine  and  one-half  glue  is 
fairly  rigid.  Flexible  glue  compounds  are  used  in  book  bindings, 
printers'  rolls,  and  for  other  purposes. 

Failure  of  Glue. — Heat  and  moisture  are  common  enemies  of 
glue.  All  glues  soften,  more  or  less,  under  the  influence  of  water; 
but  some  kinds  offer  more  resistance  than  others.  The  grades 
that  last  longest  when  exposed  to  moisture  are  sometimes  re- 
ferred to  as  "waterproof  glues,"  but  should  not  be  confused  with 
special  mixtures  that  are  also  known  as  "  waterproof  "  or  "marine 


408  ORGANIC  STRUCTURAL  MATERIALS 

glues."  Resistance  to  moisture  may  be  increased  artificially  by 
the  application  of  formalin.  The  other  common  enemy  referred 
to,  that  is,  dry  heat,  causes  some  glues  to  shrink  and  become 
brittle. 

Selection. — Glue  may  be  perfectly  good,  yet  may  be  unsuitable 
for  the  work  in  which  it  is  employed.  In  the  glues  that  are  used 
in  carpentry,  it  is  important  that  adhesive  powers  should  be 
highly  developed;  whereas  in  some  other  glues,  that  are  valued 
for  other  purposes,  other  properties  are  at  least  equally  important. 

Taken  all  in  all,  the  best  glues  with  woods  are  those  made  from 
hidestock,  although  glues  made  from  footstock  are  also  prized 
in  joinery,  because  the  sinews  that  adhere  to  the  hoofs  yield 
material  that  possesses  high  adhesive  value.  Glues  made  from 
acid-treated  bones  appear  well,  but  sometimes  crack  when  used 
under  conditions  that  exist  in  the  United  States,  and,  for  this 
reason,  are  often  less  desirable  in  joinery  than  are  some  others. 

All  glues  look  much  alike  to  casual  observers.  Those  who  use 
large  quantities  of  this  material  learn  by  experience  the  kinds 
best  fitted  for  their  needs;  but  those  who  use  glue  only  occa- 
sionally should  refer  their  problems  to  reliable  manufacturers, 
who  will  suggest  the  grades  that  are  best  fitted  to  meet  their 
requirements. 

APPLICATION.— The  strength  and  durability  of  a  joint  are 
influenced  by  the  way  in  which  the  glue  is  applied.  The  glue  may 
be  good  and  appropriate,  but  the  joint  will  fail  unless  the  glue 
is  applied  in  the  proper  manner.  Several  details  are  important: 
(1)  the  glue  must  be  carefully  dissolved;  (2)  the  wood  must  be 
ready  to  receive  the  dissolved  glue;  and  (3)  the  wood  and  glue 
must  be  brought  together  in  a  way  that  has  been  shown  by 
experience  to  produce  lasting  results. 

1.  Dissolving  the  Glue. — There  are  two  parts  to  this  process. 
First,  the  glue  must  be  softened,  and  for  this  purpose,  it  is  placed 
in  from  two  to  four  times  its  weight  of  cold  water.     Broken 
glues  must  remain  in  the  water  for  several  hours,  but  ground 
glues  often  soften  sufficiently  in  five  or  ten  minutes.     Second, 
after  the  removal  of  the  excess  water,  the  soft  arid  swollen  mass 
must  be  warmed  until  it  is  thoroughly  dissolved.     Care  must  be 
taken  to  avoid  direct  or  high  heat.     Many  devices  are  available 
to  protect  glue  from  excessive  heat  during  this  part  of  the  process. 

2.  Preparing  the   Wood. — The  wood  should  be  clean,  well- 
seasoned,  and  sufficiently  warm.     The  surfaces  of  close-grained 


CATTLE  AND  FISH  GLUES  409 

woods  should  be  roughened,  and  the  same  treatment  should  be 
extended  to  other  woods  when  necessary.  The  film  that  forms 
over  the  surface  of  melted  glue  when  the  warm  solution  is  chilled 
by  contact  with  the  air  is  duplicated  when  the  solution  is  applied 
to  the  normally  cooler  surfaces  of  woods.  For  this  reason,  cabi- 
net makers  warm  pieces  of  wood  that  are  to  be  joined  by  glue. 
Care  is  necessary  here  also,  since  high  heat  is  injurious  to  wood 
as  well  as  to  glue. 

3.  Completing  the  Joint. — Penetration,  warmth,  and  pressure 
are  necessary.  The  glue  must  sink  into  the  "take  hold"  of  the 
wood.  To  bring  about  this  penetration,  the  differences  in  pene- 
trability of  close-grained  and  hard-grained  woods,  must  be  kept 
in  mind.  The  necessity  for  warmth  has  already  been  explained. 
Pressure  is  very  necessary  because  some  time  must  elapse  before 
the  glue  can  set  sufficiently  to  hold  the  parts  together;  the  parts 
are  therefore  held  in  presses  during  this  interval.  The  object 
throughout  is  to  bring  the  pieces  together  in  such  a  way  that  the 
joint  will  be  at  least  as  strong  as  the  wood. 

A  series  of  axioms  relating  to  the  application  of  cattle  glues 
given  by  Fernbach  is  as  follows:1 

"When  two  surfaces  of  split  wood  are  laid  together,  the  hold  of  the 
glue  is  the  same  whether  the  fibers  are  laid  parallel  or  crosswise  to  one 
another. 

"The  value  of  a  wood  joint  is  dependent  upon  the  union  of  the  glue 
with  the  fiber  of  the  wood.  For  glue  to  be  properly  effective,  it  must 
penetrate  the  pores  of  the  wood;  and  the  greater  this  penetration,  the 
more  substantial  the  joint. 

"All  other  factors  being  equal,  glues  that  dry  slowly  are  invariably 
stronger  in  the  joint  than  those  that  dry  rapidly. 

"Except  in  the  case  of  veneering,  both  surfaces  of  the  wood  should  be 
properly  glued  before  junction. 

"Do  not  use  thick  solutions  of  glue  for  joint-work.  They  congeal 
too  quickly,  and  hence  fail  to  penetrate  the  pores  of  the  wood,  yielding, 
as  a  result,  a  weak  joint.  In  every  case,  the  glue  must  be  worked  well 
into  the  wood  with  a  brush,  much  in  the  same  manner  as  a  coat  of  paint 
is  applied. 

"If  glue  is  applied  to  hot,  as  distinct  from  warm,  wood,  all  the 
water  of  the  glue  solution  would  be  absorbed  by  the  wood,  leaving 
a  thin  inadhesive  coating  of  glue  at  the  surfaces  of  the  joint,  which, 
if  made  in  this  fashion,  will  hold  only  a  limited  time." 

1  "Glues  and  Gelatine"  (1907  Edition,  p.  106). 


410  ORGANIC  STRUCTURAL  MATERIALS 

The  action  of  glue  in  a  joint  is  thus  described  by  Hewitt:1 

"Glue  forms  a  true  solution  with  water  at  temperatures  above  one 
hundred  and  forty  degrees  Fahrenheit.  It  passes  out  of  solution  gradu- 
ally as  it  cools  below  this  point.  The  molecules  of  glue  then  join  with 
one  another  and  the  water  that  is  excluded  occupies  the  vacant  places 
in  the  resulting  tissue. 

"Glue  should  be  in  solution  as  it  passes  into  the  pores  of  the  pieces 
that  are  to  be  joined.  To  insure  this  the  temperature  of  the  pieces 
should  be  raised  to  a  point  somewhat  in  excess  of  one  hundred  and  forty 
degrees.  The  glue  and  water  will  then  pass  in  together  and  a  strong 
net  work  is  formed  as  the  glue  separates  from  the  water. 

"Ordinary  carpenter's  glue  contains  from  forty  per  cent,  to  fifty  per 
cent,  of  pure  gelatine.  The  balance  is  glue  peptones,  caused  by  gelatine 
breaking  down  at  various  stages.  The  true  gelatine  will  not  adhere  if 
the  glue  is  applied  at  temperatures  below  one  hundred  and  forty  degrees 
Fahrenheit.  Some  adhesion  is  caused  by  the  peptone  substances  but 
the  joint  is  not  as  strong  as  it  should  be.  The  matter  is  complex  but 
the  principle  is  that  the  glue  or  gelatine  should  be  applied  when  suffi- 
ciently hot  and  concentrated." 

PROTECTION  OF  JOINTS.— Since  heat  and  moisture  are  the 
common  enemies  of  glue,  all  joints  in  which  glue  is  used  should  be 
protected  from  these  known  elements  of  failure  as  far  as  this  is 
possible. 

Protection  from  Heat. — Some  glues  resist  the  influence  of  dry 
heat  better  than  other  glues.  It  is  probable  that  the  best  results, 
when  this  material  is  used  with  wood,  are  obtained  by  the  use  of 
selected  glues  made  from  hides.  Bone  glues  are  less  stable, 
more  likely  to  shrink  and  become  brittle  under  the  influence  of 
dry  heat. 

Aside  from  the  glue,  the  wood  itself  requires  attention.  It 
is  necessary  that  the  pieces  to  be  joined  should  be  dry  and  well- 
seasoned.  Some  failures  of  glued  joints  can  be  traced  to  the 
shrinking  and  warping  of  the  woods  themselves. 

Protection  from  Moisture. — Resistance  to  moisture  may  be 
increased  by  the  use  of  selected  glues. .  Formalin,  if  used  in  this 
connection,  should  be  applied  after  the  joint  has  become  dry. 
The  glue  may  swell  a  little,  but  the  antiseptic  renders  it  compara- 
tively insoluble,  and  glue  treated  in  this  way,  never  decays  under 
ordinary  conditions.  After  the  work  has  become  dry,  it  should 
be  protected  by  paint  or  varnish. 

1  Correspondence  quoted  by  permission. 


CATTLE  AND  FISH  GLUES  411 

Joints  can  be  protected  so  that  they  will  resist  seemingly  adverse 
conditions  for  a  long  time.  This  is  shown  by  boats  manufactured  by 
the  Racine  Boat  Company.  The  hulls  of  these  boats  were  built  of 
layers  of  thin  veneer  glued  crosswise  upon  one  another,  and  it  is  said 
that  they  remained  sound  as  long  as  they  were  protected  by  paints  or 
varnishes.  "  The  actual  use  of  the  boats  demonstrated  that  they  require 
considerable  care.  They  could  not  be  left  in  the  water  or  sun  indefi- 
nitely. The  strong  rays  of  the  sun  on  the  boats  in  the  water  would 
blister  the  veneer  and  the  blisters  would  naturally  form  checks.  This 
was  overcome  by  putting  on  little  copper  patches.  Boats  that  had  good 
care  have  stood  for  twenty-five  years.  There  are  still  some  in  existence 
and  the  owners  write  that  they  would  not  sell  them  for  any  cost."1 

DURABILITY  OF  JOINTS.— The  durability  of  a  joint  must  be 
distinguished  from  the  durability  of  the  glue  used  in  the  joint.  The 
glue  itself  may  be  good  and  appropriate,  but  the  joint  will  fail  if 
the  glue  has  not  been  well  applied,  or  if  the  joint  has  not  been 
properly  protected.  Glue  can  be  selected,  applied,  and  protected 
in  such  a  way  that  the  work  will  last  indefinitely. 

FISH  GLUES 

SOURCES.— The  dry  forms  known  as  isinglass  are  prepared 
from  the  swimming  bladders  of  certain  fishes.  Dry  fish  glue  or 
isinglass  is  seldom  used  in  carpentry  and  is  mentioned  in  this 
place  only  for  the  sake  of  completeness.  Ordinary  or  liquid 
fish  glues  can  be,  but  seldom  are,  prepared  from  isinglass. 
These  forms  are  normally  extracted  from  the  heads,  skins,  and 
bones  of  cod,  cusk,  and  other  fishes. 

The  best  isinglass  is  made  from  sturgeon  in  Russia.  American  isin- 
glass is  prepared  from  the  swimming  bladders  of  cod  and  hake;  there 
are  other  sources  in  other  countries.  Isinglass  is  nearly  colorless,  and 
nearly  tasteless,  and  is  used  chiefly  in  medicines,  confections,  and  as  an 
agent  for  clarifying  liquids  (see  also  " gelatine").  As  cattle  glues  are 
normally  solids,  so  fish  glues  are  normally  liquids.  Much,  if  not  most, 
of  the  liquid  glue  manufactured  in  the  United  States  is  drawn  from  the 
skins,  bones,  and  other  waste  now  separated  from  the  flesh  of  cod  before 
the  latter  is  marketed.  Many  thousands  of  tons  of  this  stock  are  pro- 
duced on  the  New  England  coast  alone  every  year. 

MANUFACTURE. — Some  liquid  fish  glues  are  prepared  by 
boiling  the  sounds  of  cod  and  hake  in  water.  But  by  far  the 
larger  part  is  prepared  as  follows:  The  heads,  skins,  and  bones 

1  Correspondence  with  Racine  Boat  Manufacturing  Company  quoted  by 
permission. 


412 


ORGANIC  STRUCTURAL  MATERIALS 


containing  the  glue  are  freed  from  salt  and  dirt  and  are  then 
subjected  to  processes  of  extraction  that  resemble  those  em- 
ployed in  the  preparation  of  cattle  glues.  Preservatives  are 


FIG.  81. — Fish  sounds,  Nova  Scotia. 

added,  and  the  characteristic  fish  odor  is  disguised  by  adding 
essences.  The  results  are  not  dried,  but  are  marketed  in  liquid 
form. 


CATTLE  AND  FISH  GLUES 


413 


PROPERTIES. — Fish  glues  are  powerful  adhesives,  but  they 
do  not  always  sink  easily  into  close-grained  woods.  The  liquid 
form  is  convenient  because  it  makes  it  possible  to  use  the  glue 
without  further  preparation.  Fish  glue  is  thick  and  often  be- 
comes thicker  when  cold;  and,  at  such  a  time,  it  must  often 
be  warmed  before  it  can  be  poured  from  the  can  or  barrel  in 
which  it  is  stored.  Small  quantities  of  glue  are  easily  thinned 
by  the  addition  of  water,  vinegar,  or  acetic  acid,  or  by  warmth. 


FIG.  82. — Typical  fish  glue. 

Fish  glues  are  particularly  convenient  with  small  or  occasional 
pieces  of  work  that  must  be  undertaken  where  facilities  for 
preparing  joints  of  cattle  glue  do  not  exist.  Their  use  with  woods 
is  limited  because  cattle  glues  are  cheaper,  and,  in  the  majority 
of  cases,  sufficiently  good.  Large  quantities  of  fish  glues  are 
employed  for  gumming  labels,  stay-papers,  etc. 

Selection. — Classification  is  based  primarily  upon  the  source  of 
the  glue,  and  secondarily,  upon  the  body  and  color  of  the  glue. 
The  better  grades,  which  alone  should  be  used  with  woods,  are 
made  from  the  skins  of  cod  and  cusk,  while  less  desirable  grades 
are  made  from  the  heads,  bones,  fins  and  tails  of  the  same  fishes. 


414  ORGANIC  STRUCTURAL  MATERIALS 

Fish  glues  are  presented  under  labels  and  can,  therefore,  be  readily 
selected  by  customers.  Special  problems  should  be  submitted  to 
manufacturers. 

APPLICATION. — Fish  glues  do  not  have  to  be  dissolved,  and 
pieces  of  wood  to  be  joined  by  them  do  not  have  to  be  heated. 
Aside  from  this,  the  application  of  these  glues  resembles  that  of 
cattle  glues.  In  both  cases,  the  glue  should  be  made  to  penetrate 
as  far  as  possible,  and  in  both  cases,  the  pieces  to  be  joined  should 
be  held  in  place  firmly  until  the  joint  has  had  time  to  set.  Some 
directions  prepared  by  the  Russia  Cement  Company  of  Glouces- 
ter, Massachusetts,  relating  to  the  application  of  fish  glues,  are 
as  follows:1 

"The  joint  should  first  be  made  to  fit  as  accurately  as  possible.  A 
thin  coating  of  glue  is  allowed  to  set  which  will  take  only  a  few  minutes. 
While  the  glue  is  still  tacky,  another  coating  of  glue  should  be  used,  and 
the  joints  rubbed  together,  plenty  of  time  being  taken  to  force  out  all  the 
air,  so  that  there  will  be  no  air  bubbles,  and  so  that  the  entire  surface 
to  be  glued  will  be  covered  with  a  thin  film  of  glue.  Pressure  should 
be  used  so  that  only  a  small  amount  of  glue  is  left,  as  too  much  glue  is 
injurious  as  well  as  too  little.  Pressure  should  be  kept  up  until  the  glue 
is  quite  dry.  If  the  above  directions  are  followed,  any  piece  of  wood 
should  give  before  the  glue. 

"There  is  a  certain  knack  even  in  following  the  above  directions,  and 
the  only  way  to  obtain  good  work  on  animal  as  well  as  fish  glue  is  by 
experience  in  the  use  of  particular  glues  for  particular  woods,  and  this 
can  only  be  acquired  by  time.  There  is  no  absolute  rule  which  can  be 
followed." 

SOME  USES  OF  GLUE 

With  woods,  glues  are  used  to  wholly  or  partly  replace  nails; 
and  they  are  also  used  in  veneered  or  "built-up"  work,  such  as  is 
called  for  in  cabinet  making,  parquet  floors,  and  the  bodies  of 
fine  carriages.  The  latter  field  is  so  important  as  to  warrant 
notice.  The  fact  that  glues  are  used  for  other  purposes  than  to 
join  woods  has  already  been  noted. 

VENEERS. — This  term  is  applied  to  thin  slices  of  wood  that 
are  later  fastened  to,  or  reinforced  by,  other  pieces  of  wood. 
Veneers  are  cut  with  knives,  or  with  saws.  The  first  method, 
which  is  often  preferred  with  more  valuable  woods,  is  compara- 
tively economical  as  to  material,  while  the  latter  method  is 

1  Correspondence  quoted  by  permission. 


CATTLE  AND  FISH  GLUES 


415 


easier  as  to  labor  but  causes  much  of  the  log  to  be  lost  in  sawdust. 
Rotary-cut  veneers  are  broad  ribbons  pared  from  the  surfaces  of 
revolving  logs.  There  are  also  plain-cut  and  quarter-cut  veneers 
which  are  prepared  as  is  indicated  by  their  names. 

Veneers  ordinarily  vary  in  thickness  between  one-thirtieth  of  an  inch 
and  one-quarter  of  an  inch.     Veneers  as  thin  as  one  tw(5-hundredth  of 


FIG.  83. — Large  double-cylinder  veneer  press.1 

an  inch  can  be  prepared,  but  the  value  of  such  sheets  is  lessened  by  the 
fact  that  the  glues  used  to  fasten  them  are  liable  to  soak  through  and 
become  evident  on  the  outer  surfaces.  Most  inside  needs  are  met  by 
thicknesses  between  one-thirtieth  of  an  inch  and  one-eighth  of  an  inch. 
Veneers  that  are  to  be  exposed  to  the  weather  should  be  thicker  than 
one-eighth  of  an  inch.  Veneers  that  are  one-quarter  of  an  inch  or  more 
in  thickness  are  usually  classified  as  thin  lumber. 

1  Photograph  courtesy  Hydraulic  Press  Manufacturing  Company. 


416 


ORGANIC  STRUCTURAL  MATERIALS 


Preparation  of  Veneered  Work.  —  The  form  to  be  covered  is 
prepared  of  white  pine,  or  some  other  clean,  and  uniformly 
grained  wood  that  receives  glue  in  a  satisfactory  manner. 
__  _  ,  This  foundation  is  termed  the  "core." 

Another  piece,  called  the  "caul," 
the  surface  of  which  coincides  with 
that  of  the  core,  is  then  made  ready. 
The  pieces  of  veneer  are  fitted  over 
the  surface  of  the  core,  glued  in 
place,  and  held  there  intimately  by 
means  of  the  caul.  The  entire 
series,  composed  of  core,  glue, 
veneer,  and  caul,  is  then  placed  in  a 
press  where  it  remains  until  the  glue 
is  dry.  Curved,  irregular,  and  in- 
tricate surfaces  are  correspondingly 
harder  to  prepare  than  plain  surfaces. 
Door  frames  are  made  by  gluing 
strips  of  wood  to  one  another  and 
covering  them  with  thick  veneers, 
or  "thin  lumber."  Chair  seats  are 
prepared  by  gluing  layers  of  wood, 
of  equal  thickness,  crosswise  to  one 
another.  The  names  three-ply  or 
five-ply  are  used  where  three  or  five 
thicknesses  of  wood  are  thus  fastened 
together.  The  roofs  of  many  car- 
riages are  made  by  covering  three- 
ply  roofing  with  heavy  duck,  slushed 
on  and  tacked  at  the  edges.  The 
use  of  veneers  in  building  hulls  of 
small  boats  has  been  alluded  to. 

Inlaid  Work.  —  This  is  prepared  by 
fastening    a    sheet     of    light-colored 


sheet    of     darker     wood,      such     as 

mahogany.  A  design  is  traced  upon  the  upper  sheet,  and  a 
sharp  knife  is  passed  over  the  design  so  as  to  cut  through  both 
sheets  alike.  The  figures  cut  from  the  lighter-tinted  wood  are 
inserted  within  the  corresponding  vacant  spaces  in  the  darker 
wood,  or  vice  versa,  and  the  sheet  with  insertions  is  glued  upon  a 


PLATE  XX.     APPLICATION  OF  GLUE  IN  LARGE  CURVED  JOINT 


CATTLE  AND  FISH  GLUES  417 

core  of  seasoned  wood.  There  are  many  details  and  applica- 
tions. 

Reasons  for  Preferring  Veneered  Work. — Some  reasons  for 
preferring  veneered  work  are  as  follows: 

Stability. — The  natural  tendency  to  warp  and  check  is  less 
when  well-seasoned  pieces  of  wood  are  glued  crosswise  to  one 
another.  Results  obtained  in  this  way  are  stronger,  better,  more 
rigid,  and  lighter  in  weight,  than  when  solid  wood  is  employed. 

Appearance. — The  best  and  most  beautifully  figured  pieces  of 
wood  are  often  small.  Such  perfect,  attractive,  but  small  pieces 
can  be  sliced,  and  the  slices  joined  together  so  accurately,  over  a 
core  of  some  less  desirable  wood,  that  the  seams  cannot  easily  be 


FIG.  85. — Portion  of  three-ply  panel. 

discovered.     A  large  surface  of  perfect  and  uniformly  beautiful 
wood  is  thus  obtained. 

Economy. — As  a  matter  of  fact,  veneered  work  is  usually  more 
costly  than  solid  work  of  equal  dimensions.  It  is  cheaper  than 
solid  work  only  when  the  saving  of  material  is  enough  to  more 
than  offset  the  extra  expenditure  for  labor.  From  the  viewpoint 
of  material,  the  case  is  the  same  as  when  one  metal  is  plated  with 
another;  but  from  the  viewpoint  of  labor,  the  cost  of  preparing, 
fitting,  and  gluing  thin  sheets  of  wood  over  a  curved  or  irregular 
surface,  or  even  one  that  is  flat,  is  greater  than  the  cost  of  pre- 
paring the  equivalent  in  solid  wood. 


METHODS  OF  TESTING  GLUES 

Cattle  Glues. — The  adoption  of  a  standard,  the  selection  of  a  sample, 
and  the  estimate  of  the  appearance,  fracture,  odor,  acidity,  grease  con- 
tent, viscosity,  foam,  and  strength  of  the  sample  are  important. 

Standards. — Standards  are  necessary  for  purposes  of  comparison. 
The  Cooper  glues  have  been  used  for  this  purpose,  since  those  who  make 


418  ORGANIC  STRUCTURAL  MATERIALS 

these  glues  seem  able  to  maintain  very  uniform  products.  It  is  said 
that  the  properties  of  these  glues  have  remained  constant  during  the 
last  fifty  years. 

Samples. — The  selection  of  any  sample  is  important.  In  this  case. 
portions  drawn  systematically  from  several  parts  of  every  package 
should  be  mixed,  ground,  mixed  again,  and  then  divided  so  that  the 
final  sample  will  weigh  about  six  ounces. 

If  glues  have  been  mixed,  the  parts  should  be  separated  from  one 
another,  and  each  part  should  be  tested  separately.  The  separation 
of  separate  fragments  of  dissimilar  glues  from  one  another  is  possible 
because  of  color  distinctions  that  usually  exist.  It  is  not  enough  to 
accept  the  samples  presented  by  agents;  the  final  deliveries  also  should 
be  tested. 

Appearance. — Large  and  irregular  air  bubbles  indicate  decomposition. 
Smooth  and  glossy  surfaces  are  desirable  but  not  essential.  The  ap- 
pearance of  a  glue  may  warrant  its  rejection. 

Fracture. — Fractures  vary  with  moisture  and,  therefore,  with  the 
weather  and  is  seldom  a  criterion.  Similar  pieces  break  differently  at 
different  tunes.  Glues  made  from  acid-treated  bones  generally  show 
bright,  clean  fractures. 

Odor. — Odor  may  be  due  to  the  character  of  the  stock;  or,  it  may  be 
due  to  deterioration  in  the  glue.  Glues  made  from  goats,  sheep,  oxen, 
and  other  animals,  sometimes  possess  characteristic  odors,  which  are 
often  changed  as  a  result  of  boiling.  The  odor  that  arises  from  a  hot 
solution  of  glue  should  indicate  any  decomposition  that  has  taken  place 
after  the  glue  has  been  boiled. 

Acidity. — The  presence  of  acid  is  not  an  indication  of  the  way  in 
which  the  glue  was  manufactured,  since  a  little  acid  is  sometimes  added 
after  boiling.  Sulphurous  acid  is  often  used  to  bleach  glue  and  to  pre- 
vent its  decay.  A  slightly  acid  glue  is  often  to  be  preferred. 

Grease. — Grease  is  sometimes,  but  not  always,  undesirable.  The 
properties  of  some  glues,  as  those  used  for  moulding,  picture  frames,  and 
some  other  purposes,  may  even  be  improved  by  the  presence  of  grease. 
Such  desirability  is  influenced  or  determined  by  the  form  in  which  the 
grease  exists,  which  may  be  in  large  globules,  or  in  the  form  of  an  emul- 
sion. Of  these  two  forms  the  latter  is  less  objectionable.  The  presence 
of  grease  may  be  detected  as  follows:  A  few  grains  of  some  aniline  color 
that  will  dissolve  easily  in  water  are  placed  on  a  sheet  of  clean  white 
paper.  A  flat  brush  is  dipped  in  a  warm  solution  of  the  glue,  and  then 
hastily  drained.  The  brush  is  applied  to  the  color  so  as  to  dissolve  it, 
and  is  then,  without  being  lifted,  swept  across  the  remaining  surface 
of  the  paper.  Any  grease  that  is  present  will  appear  in  the  form  of 
spots.  Some  experimenters  prefer  to  mix  the  aniline  color  with  the  glue 
at  the  start.  The  presence  of  grease  in  fine  emulsion  is  not  always  thus 


CATTLE  AND  FISH  GLUES 


419 


revealed,  since  part  of  it  may  escape  notice  if  the  globules  are  finely 
divided. 

Viscosity. — A  viscous  liquid  is  one  that  moves  slowly  under  the  in- 
fluence of  any  force.  The  molecules  of  such  a  liquid  adhere  to  one 
another  and  do  not  move  freely  among  themselves. 

The  degree  of  viscosity  in  a  solution  of  glue  is  sometimes  relied  upon 
as  an  indication  of  strength,  but  is  a  dangerous  criterion,  since  viscosity 
may  be  influenced  by  the  presence  of  foreign  substances.  For  example, 
a  small  quantity  of  alum  will  greatly  increase  viscosity  without  other- 
wise improving  the  glue. 

The  degree  of  viscosity  may  be  measured  by  noting  the  number  of 
seconds  required  for  the  passage  of  50  c.c.  of  glue  solution  through  the 


FIG.  86. — Engler's    viscosimeter. 

orifice  of  a  standard  burette,  pipette,  or  other  vessel.  Armour  &  Com- 
pany test  solutions  prepared  by  dissolving  one  part  of  the  glue  in  five 
parts  of  water,  and  hold  the  solutions  thus  formed  at  temperatures  of 
150  degrees  Fahrenheit  while  they  are  passing  through  the  orifices. 

Foam. — Minute  bubbles  usually  appear  when  a  solution  of  glue  is 
agitated.  These  may  shortly  break  and  disappear,  or  they  may  remain 
for  some  time;  and,  in  the  latter  case,  the  presence  of  some  foreign  sub- 
stance, such  as  lime-soap,  may  be  suspected.  "Permanent  foam"  may 
be  desirable  in  the  case  of  some  confectioners'  gelatines,  but  it  is  not 
desirable  in  the  substances  now  being  considered. 

Foam  is  measured  in  specially  graduated  vessels.  A  hot  solution  of 
glue,  placed  in  one  of  these  vessels,  is  beaten  or  churned  for  some  definite 
time,  such  as  hah"  a  minute.  Negligible  quantities  of  foam  will  shortly 
disappear,  while  larger  quantities  of  more  "permanent  foam"  may  reach 
to  the  various  graduations  in  the  vessel. 

Strength. — The  behavior  of  a  piece  of  glue  while  being  bent  is  some- 


420  ORGANIC  STRUCTURAL  MATERIALS 

times  taken  as  a  criterion  of  its  strength.  It  is  true  that  a  thin  piece 
of  good  glue  will  sometimes  bend  almost  double  without  breaking,  and 
that,  under  the  same  circumstances,  a  sample  of  poor  glue  will  sometimes 
break  or  crumble.  But  it  is  also  true  that  some  weak  glues  are  flexible, 
and  that  some  strong  glues  are  brittle.  It  is  not  safe  to  estimate 
strength,  even  approximately,  by  the  behavior  of  glue  during  bending. 

A  direct  method  of  testing  cements  has  been  suggested  by  Ray.1 
Blocks  of  specially  prepared  porcelain  are  employed.  One  of  the  blocks 
resembles  half  of  a  cement  briquette  such  as  is  specified  for  testing  by 
the  American  Society  of  Civil  Engineers,  and  two  of  the  blocks,  when 
joined  together,  resemble  the  complete  form  of  the  said  briquette.  The 
two  blocks  are  glued  together,  and,  after  a  sufficient  time,  are  parted  in 
a  Fairbanks  or  other  testing  machine.  It  is  hard  to  test  glue  in  an 
ordinary  wooden  joint,  because  the  glue  in  the  joint  is  usually  stronger 
than  the  wood.  The  wood  fails  first,  and  the  test  serves  to  determine 
the  strength  of  the  wood  rather  than  that  of  the  glue. 

Strength  is  usually  measured  by  comparing  the  solidity  of  a  jelly 
made  of  the  glue  to  be  tested,  with  the  solidity  of  a  jelly  made  from 
glue  of  some  standard  make.  The  comparison  may  be  made  with  a 
weighted  plunger  of  some  definite  area;  or,  the  jellies  may  be  compared 
by  pressing  them,  one  after  the  other,  with  the  finger.  Fernbach,  who 
has  made  many  tests,  regards  the  fourth  finger  of  the  left  hand  as  being 
the  most  sensitive  and,  therefore,  the  most  satisfactory  for  this  work. 
On  the  whole,  the  jelly  strength  of  a  glue  gives  the  best  practical  indica- 
tion of  its  strength. 

Fish  Glues. — Less  attention  has  been  given  to  perfecting  methods 
for  testing  fish  glues.  The  means  that  manufacturers  have  for  grind- 
ing these  glues,  and  for  judging  their  qualities,  are  apparently  suf- 
ficient. The  fact  that  fish  glues  are  sold  under  labels  is  a  safeguard 
to  consumers. 


Thesis,  New  York  University,  1902. 


CHAPTER  XVII 

INDIARUBBER    AS    A    STRUCTURAL    AND    MACHINE    MATERIAL. 

SOURCES,    PREPARATION,    PROPERTIES,   AND   USES   OF 

INDIARUBBER 

The  fact  that  rubber  is  used  to  some  extent  in  construction, 
transportation,  and  manufacture,  as  in  flooring,  automobile 
tires,  and  belts,  is  sufficient  to  warrant  it's  rating  as  a  structural 
and  machine  material. 

As  sugar  is  known  to  exist  in  a  variety  of  non-related  and  dis- 
similar plants,  such  as  sugar  beets,  sugar  cane,  and  sugar  maple 
trees,  so  the  constituents  of  the  tough,  impermeable,  and  very 
elastic  substance  known  as  Indiarubber,  are  known  to  exist  in  a 
number  of  plants  that  are  not  related  to  one  another. 

The  trees,  vines,  and  shrubs  in  which  the  constituents  of  India- 
rubber  are  known  to  be  present  may  be  numbered  by  the  hundred ; 
but  the  trees,  vines,  and  shrubs  from  which  it  is  actually  obtained 
in  commercial  quantities  are  comparatively  few.  The  plants 
from  which  rubber  is  thus  obtained  grow  in  a  belt  that  extends 
around  the  world.  This  belt  includes  parts  of  Mexico,  Central 
America,  South  America  north  of  Argentina,  Africa  from  Cape 
Colony  to  Sahara,  Oceanica,  Java,  Sumatra,  Borneo,  India, 
The  Malay  States,  and  the  Philippines. 

The  constituents  of  Indiarubber  exist  in  a  milk-like  fluid  or 
latex  that  is  present  in  and  characteristic  of  most  of  the  plants 
from  which  Indiarubber  is  obtained.  The  latex  itself,  the 
methods  by  which  it  is  collected,  and  those  by  which  it  is  made  to 
yield  rubber,  are  all-important. 

REFERENCES. — "  Crude  Rubber  and  Compounding  Ingredients,"  Pearson 
(Indiarubber  Publishing  Company,  New  York,  1909) ;  Files  of  Indiarubber 
World;  Journal  of  Society  of  Chemical  Industry;  "The  Culture  of  the  Cen- 
tral American  Rubber  Tree,"  Cook  (United  States  Bureau  of  Plant  In- 
dustry, Bulletin  No.  49);  "Rubber  Cultivation  for  Porto  Rico,"  Cook 
(United  States  Division  of  Botany,  Circular  No.  28);  "Indiarubber" 
(Special  Consular  Reports,  Government  Printing  Office,  1892);  "Guayule, 
A  Rubber  Plant  of  the  Chihuahuan  Desert,"  Lloyd  (Carnegie  Institution, 
Bulletin  No.  129);  "Indiarubber  and  Gutta  Percha,"  Seeligmann,  Torril- 
hon  and  Falconnet  (Scott,  Greenwood  &  Company,  London,  1910); 
"Rubber,"  Schidrowitz  (Methune  &  Company,  London,  1911). 

421 


422 


ORGANIC  STRUCTURAL  MATERIALS 


Latex. — This  term  applies  generally  to  the  milky  juice  secreted 
by  certain  shrubs,  vines,  and  trees,  In  some  cases  the  latex 
yields  no  rubber;  in  others  it  does  yield  rubber,  but  this  is  not 


FIG.  87. — Appearance  of  Hevea  rubber  latex. 

used.1     Still  other  latex  is  known  by  experience  to  produce  rubber 
satisfactorily. 

1  The  latex  of  the  common  milkweed  is  a  familiar  example.  When  this 
fluid  dries  upon  the  fingers  it  yields  an  elastic,  sticky  substance  which  con- 
tains resins,  other  compounds  and  a  residue,  the  empirical  composition  of 
which  is  the  same  as  that  of  crude  rubber. 


INDIARUBBER  423 

Latex  must  be  distinguished  from  sap.  The  latter  fluid  occu- 
pies a  large  proportion  of  the  entire  stem,  and  is  common  to  all 
plants;  while  latex,  which  is  restricted  to  certain  species,  is  con- 
fined in  delicate  tubes  that  run  lengthwise  throughout  the  inner 
part  of  the  bark.  Sap  is  obtained  by  boring  holes  through  the 
bark  and  outer  sapwood;  while  latex  is  obtained  by  cutting  across 
the  bark  alone. 

The  appearance  of  latex  is  similar  to  that  of  cow's  milk.  It 
is  a  thin,  watery  emulsion,  made  up  of  cream-like  globules  sus- 
pended in  a  thinner  liquid  of  another  composition.  These  two 
parts  remain  mingled  in  emulsion  until  certain  physical  or 
chemical  changes  cause  them  to  separate.  The  creamy  part  of 
latex  obtained  from  the  plants  of  the  Indiarubber  series  is  the 
basis  of  indiarubber. 

It  is  not  known  whether  rubber  exists  as  such  in  the  latex, 
or  whether  it  is  due  to  recombinations  caused  by  chemical  or 
physical  changes.  It  is  enough  to  assume  that  rubber  exists  in 
the  latex  much  as  butterfat  exists  in  cream,  and  that  it  is  obtained 
from  the  latex  by  chemical  or  other  manipulations  that  suggest 
the  churning  to  which  butterfat  is  subjected  during  the  preparation 
of  butter. 

The  proportions  of  rubber  in  the  latex  vary  considerably.  The 
composition  of  a  sample  of  Ceylon  Para  latex,  described  in  the 
Encyclopedia  Britannica,  was  as  follows:1  Water,  55.15  per 
cent.;  Caoutchouc  (rubber),  41.29  per  cent.;  Proteids,  2.18 
per  cent.;  Sugar,  etc.,  0.36  per  cent.;  Ash  (salts),  0.41  per  cent. 
The  best  latex  may  yield  as  much  as  50  per  cent,  of  rubber. 
Cook  states  that  six  pounds  of  fresh  rubber  were  obtained  from 
ten  pounds  of  latex,  but  that  this  rubber  shrank  to  three  pounds 
before  the  end  of  the  year.2 

Collection  of  Latex. — Details  vary  with  species  and  localities. 
Some  plants  produce  larger  quantities  of  latex  and  then  require 
rest,  while  others  yield  smaller  quantities  at  a  time  but  yield 
these  smaller  quantities  frequently.  The  comparative  advan- 
tages of  longitudinal,  oblique,  transverse,  and  spiral  cuts,  and 
of  tools  used  to  make  these  cuts,  have  received  much  attention. 
The  object  is  to  so  adjust  time  and  frequency  of  tapping  with 
the  peculiarities  of  species  as  to  secure  maximum  yields  during 

1  Quoted  by  permission  of  The  Cambridge  University  Press. 

2  "The  Culture  of  the  Central  American  Rubber  Tree,"  Cook  (United 
States  Bureau  of  Plant  Industry,  Bulletin  No.  49,  p.  75). 


424  ORGANIC  STRUCTURAL  MATERIALS 

the  longest  possible  terms  with  the  least  possible  harm  to  the 
trees. 

Pearson  describes  the  collection  of  wild  Para  rubber  as  follows : 


FIG.  88. — Application  of  coagulant  (alcohol)  to  latex  shown  in  preceding 

figure. 

"A  man  locates  from  100  to  150  rubber  trees  and  cuts  a  narrow  path 
through  the  jungle  from  tree  to  tree.  He  starts  out  early  in  the  morning 
with  a  little  hatchet  and  an  armful  of  tin  cups.  He  makes  a  few  cuts 
on  each  tree  and  sticks  the  cups  under  to  catch  the  latex.  .  .  .  The 
next  day  he  goes  through  the  same  operation  on  the  same  trees,  making 
fresh  cuts.  He  continues  this  for  several  weeks,  sometimes  months. 
More  than  this,  he  taps  the  same  trees  year  after  year  for  many  years." 


INDIARUBBER 


425 


Rubber  Obtained  from  Latex. — The  process  by  which  rubber  is 
obtained  from  latex  is  called  coagulation.  This  term  is  used  in 
all  cases,  even  although  the  underlying  changes  may  differ  with 


FIG.  89. — Result  obtained  by  addition  of  alcohol  to  latex  shown  in  Fig.  88. 
The  white  tint  of  the  resulting  rubber  soon  gave  way  to  characteristic 
darker  color  and  the  mass  became  denser  and  much  smaller. 

the  processes  employed  and  with  different  species  of  latex.  The 
phenomena  of  coagulation  are  not  yet  perfectly  comprehended. 
Some  kinds  of  latex  coagulate  spontaneously  like  blood,  while 
others  coagulate  after  fermentation  like  milk;  still  other  kinds 


426  ORGANIC  STRUCTURAL  MATERIALS 

of  latex  coagulate  after  the  addition  of  chemicals,  and  some  do 
not  coagulate  at  all.  Among  the  materials .  and  agencies  em- 
ployed to  obtain  rubber  from  latex  are  acetic  acid,  air,  alcohol, 
alum,  heat,  lime,  lime-juice,  proprietary  compounds,  smoke  and 
sunshine.  The  accompanying  pictures  show  the  effect  of  alcohol 
upon  latex. 

An  exception  to  the  rule  that  rubber  is  derived  from  latex 
should  be  noted.  The  rubber  known  as  Guayule  is  distinct  from 
most  others  because  it  is  not  derived  from  latex,  the  rubber 
existing  as  such  in  the  cells  of  the  plants.  This  rubber  cannot  be 
obtained  by  customary  tapping  and  coagulating.  It  is  either 
dissolved  out  by  suitable  chemical  solvents,  after  the  tissues  in 
which  it  is  contained  have  been  ground  in  a  mill ;  or  else,  the  mass 
is  agglomerated,  either  with  or  without  the  assistance  of  some 
substance  like  caustic  potash  that  will  attack  the  walls  of  the 
cells  that  contain  the  rubber.1 

Much  of  the  best  wild  Para  rubber  is  obtained  by  exposing  the  latex 
to  the  smoke  of  burning  palm  nuts  (usually  Attalea  excelsa).  A  wooden 
paddle  is  dipped  into  the  vessel  containing  the  latex  and  the  thin  layer 
that  collects  upon  the  paddle  is  exposed  to  the  smoke.  In  some  districts 
coagulation  is  obtained  by  spreading  the  latex  over  the  banana-like 
leaves  of  a  species  of  Calathaea,  and  then  exposing  it  to  the  sun  and  air. 
Cook  states2  that  the  natives  of  Angola  rely  upon  the  fact  that  much 
Landolphia  latex  changes  almost  immediately  upon  exposure  to  the  at- 
mosphere, and  obtain  considerable  rubber  by  smearing  this  latex  over 
their  bodies;  the  rubber  is  cut  away  as  soon  as  the  accumulation  is 
sufficiently  thick.  There  are  many  other  ways  by  which  latex  can  be 
coagulated. 

GRADES  OF  INDIARUBBER.  Indiarubbers  may  be  grouped 
or  classified  in  several  ways.  Some  of  these  are  as  follows: 

Geographical  Classification. — From  this  standpoint  rubbers  may 
be  classified  according  as  they  come  from  major  areas  such  as 
the  Para,  Central  American,  African,  and  East  Indian  districts, 
and  also  as  they  come  from  fields  within  these  major  districts. 
Also  rubbers  are  named  from  collecting  stations,  or  trading  points 
that  are  located  within  these  minor  fields. 


1  "  Guayule,  A  Rubber  Plant  of  the  Chihuahuan  Desert,"  Lloyd  (Published 
by  Carnegie  Institution). 

2  "Rubber  Cultivation  for  Porto  Rico,"  Cook  (United  States  Division  of 
Botany,  Circular  No.  28,  p.  9). 


INDIARUBBER  427 

Para  rubber  was  formerly  divided  according  as  it  came  from  the  valley 
of  the  Upper  Amazon  and  from  islands  in  the  Lower  Amazon,  into  Up- 
river  and  Island  Para.  There  are  now  Caviana,  Cameta,  Madeira, 
Manaos,  Purus,  and  many  other  kinds  of  Para  rubber.  Central  Ameri- 
can Rubber,  or  "  Centrals,"  includes  Nicaraguan,  Guatemalan,  Mexi- 
can, Honduras,  West  Indian,  and  other  yields;  and  each  one  of  these 
includes  others,  as  for  example,  Colombian  rubber  includes  Cartagena, 
Panama,  and  other  kinds.  African  rubber  is  divided  according  as  it 
comes  from  French  West  Africa,  Sierra  Leone,  Liberia,  Gold  Coast  Col- 
ony, French  Congo,  Belgian  Congo,  East  Africa,  Madagascar,  and  other 
districts.  East  Indian  rubber  includes  Rangoon  rubber,  which  is  a 
product  of  Burma  exported  through  the  port  of  Rangoon,  Java  rubber, 
and  rubber  from  Borneo  and  other  places. 

Botanical  Classification. — The  plants  known  to  contain 
rubber  are  too  numerous  to  name  in  the  present  connection. 
The  plants  from  which  it  is  actually  obtained  in  commercial 
quantities  may  be  divided  as  they  are  trees,  vines,  and  shrubs. 

Tree  Rubber. — The  Para  or  Hevea  Rubber  Tree  (Hevea  braziliensis) 
stands  first  among  all  plants  of  every  description  that  produce  India- 
rubber.  This  tree,  which  is  the  source  of  most  Para  rubber,  is  a  native 
of  Brazil  but  has  been  transplanted  in  many  places  on  both  hemispheres. 
Its  value  depends  upon  the  quality  of  its  rubber,  and  also  upon  the  fact 
that  it  can  be  tapped  every  day  for  long  intervals.  Other  important 
trees  that  yield  Indiarubber  are  the  Central  American  Rubber  Trees 
(Castilloa  alba,  Castilloa  elastica  and  others),  and  the  Assam  Rubber 
Tree  (Ficus  elastica)  which  is  a  native  of  India,  Burma,  and  the  Malay 
Archipelago. 

Vine  Rubber. — A  large  part  of  the  supply  from  Africa  is  obtained 
from  rubber-bearing  vines  and  creepers,  of  which  there  are  many  species 
(Landolphia  owariensis,  Landolphia  heudelotii,  Landolphia  kirkii,  Lan- 
dolphia  dawei,  Landolphia  thollonii  and  others). 

Shrub  Rubber. — The  Guayule  (Parthenium  argentatuni)  has  already 
been  mentioned.1  This  shrub  flourishes  over  considerable  areas  in  the 
dry  regions  of  northern  and  central  Mexico  and  in  adjoining  parts  of 
Texas,  Arizona,  and  New  Mexico,  and  differs  from  most  rubber  produc- 
ing plants  in  that  the  rubber  exists  as  such  in  its  cells.  Special  methods 
are  employed  to  obtain  this  rubber,  and  their  discovery  has  caused  this 
shrub  to  become  very  valuable. 

Crude  and  Refined  Rubber. — The  first  term  includes 
material  as  it  arrives  from  the  forests.  Such  rubber  is  distin- 


1  "Guayule,  A  Rubber  Plant  of  the  Chihuahuan  Desert,"  Lloyd  (published 
by  the  Carnegie  Institution,  pp.  8,  9,  and  177). 


428  ORGANIC  STRUCTURAL  MATERIALS 

guished  by  the  presence  of  smaller  or  larger  quantities  of  twigs, 
bark,  dirt,  and  other  impurities  that  must  be  removed  before 
the  rubber  can  be  used,  after  which  removal  the  product  is  known 
by  the  second  term,  that  is,  as  Refined  rubber.  The  shapes  of 
the  pieces  in  which  crude  and  refined  rubber  are  presented  are 
characteristic. 

Fresh  and  Reclaimed  Rubber. — The  second  term  includes 
rubber  obtained  from  worn-out  and  discarded  rubber  articles. 
This  product  is  so  important,  that,  for  some  time  past  in  the 
United  States,  two  pounds  of  it  have  been  used  to  one  of  fresh 
rubber.  Without  Reclaimed  rubber  the  shortage  in  the  produc- 
tion of  Fresh  rubber  would  often  have  been  serious.  A  mixture 
of  fresh  and  reclaimed  rubber  is  cheaper,  and,  in  some  cases, 
better  than  fresh  rubber  alone.  Reclaimed  rubber  is  often  called 
according  to  its  origin.  Thus,  there  are  tire-tread,  hose,  gum- 
shoe, and  other  kinds  of  stock.  The  first  term,  that  is,  Fresh 
rubber,  includes  all  that  is  not  Reclaimed  rubber. 

Wild  and  Plantation  Rubber. — Wild  rubber  is  that  which 
is  obtained  by  more  or  less  primitive  processes  from  plants  grow- 
ing naturally  in  the  forest.  It  is  usually  quite  dirty  and  there 
are  other  defects,  yet-  some  of  the  best  rubber  is  of  this  kind. 
At  the  present  time,  the  larger  part  of  the  world's  supply  of  rub- 
ber is  Wild  rubber.1 

Plantation  rubber  is  obtained  from  cultivated  trees.  Tapping, 
coagulating,  and  other  details  are  attended  to  in  a  more  or  less 
scientific  manner.  Plantation  rubber  is  frequently  branded  with 
the  trademark  of  the  planter  who  then  assumes  responsibility 
for  the  quality  of  his  product.  The  quantity  of  this  kind  of 
rubber  is  increasing  every  year;  yet,  much  remains  to  be  learned 
with  regard  to  it.  It  is  known  that  some  species  do  well  in  some 
localities,  and  fail  utterly  in  others,  and  that  some  individual 
trees  grow  well  and  yet  fail  to  produce  satisfactory  quantities 
of  latex.  There  are  many  ways  in  which  failures  may  take 
place,  but,  in  spite  of  this,  as  the  following  table  (Pearson)  shows, 
rubber  planting  is  increasing  very  rapidly  in  the  Far  East. 

1  It  should  be  noted  that  the  wild  rubbers  received  at  the  present  time  are 
for  the  most  part  Para  rubbers,  and  that  in  spite  of  the  crude  methods  em- 
ployed to  collect  and  prepare  them,  the  various  grades  of  Para  rubber  are 
quite  good  and  uniform  in  quality.  This  cannot  be  said  of  much  of  the 
plantation  rubber  noted  in  the  succeeding  paragraph.  Medium  grade 
plantation  rubbers  often  exhibit  wide  variability.  High-grade  plantation 
rubbers  are,  however,  quite  uniform  in  quality. 


INDIARUBBER 


429 


Ceylon, 
pounds 

Federated   Malay 
States, 
pounds 

Total, 
pounds 

1903 

41,798 

41,798 

1904 

77,212 

77,212 

1905 

168,547 

228,800 

397,347 

1906 

327,661 

1,028,792 

1,356,453 

1907 

566,080 

2,089,085 

2,655,165 

1908 

912,125 

3,671,435 

4,583,560 

1909 

1,372,416 

7,390,643 

8,763,059 

To  August  15,  1910 

1,468,146 

7,512,102 

8,980,248 

Classification  Due  to  Form. — The  sizes  and  shapes  of  pieces 
in  which  rubber  is  originally  marketed  vary  greatly.  Some  forms 
are  associated  with  peculiar  processes  or  conditions,  or  with 
certain  districts,  or  species.  For  example,  much  plantation 
rubber  is  received  in  rough-surfaced  sheets  known  as  crepe. 
Rubber  from  Sierra  Leone  is  received  in  forms  known  as  twists, 
cakes,  and  niggers.  There  are  also  many  other  forms,  such  as 
thimbles,  balls,  nuts,  lumps,  flake,  paste,  -buttons,  oysters, 
biscuits,  tongues,  blocks,  worms,  strips,  sheets,  scrap,  and  lace. 

PREPARATION  AND  PURIFICATION  OF  RUBBER.— The 
process  employed  to  free  crude  rubber  from  mechanical  impuri- 
ties is  called  washing.  The  rubber  is  first  soaked  in  very  hot 
water  and-  is  then  passed  again  and  again  between  corrugated 
rollers  of  special  machines  that  tear  and  break  it.  At  the  same 
time  streams  of  water  are  made  to  flow  over  the  rubber  and  these 
streams  carry  away  the  impurities  that  are  exposed  by  the 
tearing  action  of  the  rolls. 

Rubber  treated  in  this  way  is  comparatively  clean,  but  much 
water  is  retained.  It  is,  therefore,  submitted  to  the  rollers  of 
another  machine  which  press  it  into  comparatively  thin  sheets, 
in  which  form  it  is  ready  to  be  dried.  The  sheets  are  either 
dried  slowly  by  natural  means,  or  they  are  dried  rapidly  under 
high  temperatures  in  rooms  prepared  for  the  purpose. 

From  this  point  details  vary  more  greatly  as  different  objects 
are  to  be  attained.  For  example,  the  rubber  must  be  "mixed." 
Aside  from  the  sulphur  used  for  vulcanization,  rubber  is  seldom 
used  alone,  but  other  substances  are  added,  the  object  being  to 
reduce  the  cost  of  the  rubber  without  destroying  its  usefulness, 
or  to  give  it  characteristics  that  cannot  be  secured  in  any  other 
way.  Sulphur,  zinc  white,  white  lead,  whiting,  oils,  rubber  sub- 


430 


ORGANIC  STRUCTURAL  MATERIALS 


stitutes,  and  many  other  materials  and  compounds  are  used  in 
this  connection. 

Several  machines  are  necessary.  A  warming  mill  or  " warmer"  is  a 
set  of  rolls,  within  which  steam  circulates.  The  mill  causes  the  rubber 
to  become  soft,  homogeneous,  and  ready  for  mixing.  The  incorporation 
of  the  several  ingredients  with  one  another  is  accomplished  in  a  mixing 
machine  or  "mixer"  designed  for  this  purpose.  A  " calender"  is  a  mill 
by  which  the  prepared  rubber  is  formed  into  sheets  from  which  it  "can 
be  more  easily  made  into  the  desired  shapes  and  sizes.  There  are 
many  combinations  and  details. 


FIG.  90. — Calender  with  coil  clutch  motor  drive.1 

Vulcanization. — The  fact  that  pure  rubber  is  influenced  by 
comparatively  moderate  changes  of  temperature  led  to  experi- 
ments that  resulted  in  the  discovery  of  the  process  called  "  vul- 
canization. "  This  discovery,  made  by  Goodyear  in  1844,  con- 
sists, briefly,  of  subjecting  rubber  to  the  influence  of  sulphur. 
The  exact  nature  of  many  details  is  not  always  divulged  by 
manufacturers.  Practically  all  rubber  is  now  vulcanized. 

The  details  of  the  processes  employed  to  secure  vulcanization 
vary  greatly.  Many  objects  are  to  be  attained  and  details 
known  to  secure  the  results  desired  are  followed.  Primarily, 
vulcanization  processes  may  be  grouped  as  they  are  Heat 
Processes  and  Non-heat  Processes. 


Photograph,  Farrel  Foundry  &  Machine  Company. 


INDIARUBBER  431 

Heat  Processes. — The  heat  may  be  wet  or  dry.  In  the  first  case, 
articles,  such  as  sheetings,  are  covered  with  French  talc,  so  that  they 
will  not  adhere  to  one  another,  or  are  wrapped  in  cloth,  and  are  then 
subjected  to  the  action  of  live  steam.  Time,  temperature,  and  pressures, 
which  latter  are  above  that  of  the  atmosphere,  are  important.  In  the 
second  case,  articles,  such  as  shoes,  coats,  and  other  black  goods,  are 
cured  in  dry,  hot  air  or  are  confined  in  moulds  and  then  placed  in  a 
steam  press.  Sometimes  rubber  is  cured  and  moulded  at  the  same  time. 
This  is  the  case  with  rubber  belts  that  are  cured  while  being  moulded 
between  the  platens  of  special  presses. 

About  six  per  cent,  of  sulphur,  based  upon  the  weight  of  the  rubber, 
is  used  in  the  vulcanization  of  the  majority  of  articles  prepared  for 
mechanical  purposes.  Press-cured  articles  often  contain  as  much  as 
eight  per  cent,  of  sulphur.  In  the  case  of  rubber  shoes  the  amount  of 
sulphur  used  is  three  per  cent.,  based  upon  the  weight  of  the  rubber. 
Larger  quantities  are  used  in  the  preparation  of  the  hard  rubber  known 
as  "vulcanite"  or  " ebonite."  As  a  rule  more  sulphur  is  used  than  is 
needed  to  combine  with  the  rubber.  The  excess  of  uncombined  sulphur 
that  remains  after  vulcanization  is  distributed  in  extremely  small  glob- 
ules throughout  the  mass,  and  eventually  appears  upon  its  surface  as  a 
grayish  powder.  In  this  connection,  it  should  be  noted  that  results  are 
often  influenced  as  much  by  the  time  and  temperature  of  vulcanization 
as  by  the  quantity  of  sulphur. 

No  action  takes  place  between  the  rubber  and  the  sulphur  until  the 
temperature  reaches  about  120  degrees  C.,  and,  even  then,  the  action 
proceeds  slowly;  but  the  action  goes  forward  more  rapidly  as  tempera- 
tures increase,  particularly  in  the  presence  of  much  sulphur.  The  tem- 
peratures required  during  the  preparation  of  mechanical  goods  vary 
between  120  degrees  C.  and  150  degrees  C.  Hard  rubber  or  vulcanite 
may  require  higher  temperatures. 

Non-heat  Processes. — These  are  of  two  kinds:  acid  vulcanization  is 
accomplished  by  dipping  the  prepared  rubber  in  a  solution  of  sulphur 
chloride  and  carbon  bisulphide,  and  then  treating  it  with  an  alkaline 
wash;  while  vapor  vulcanization  is  obtained  by  subjecting  the  rubber 
to  the  fumes  of  sulphur  chloride,  later  replaced  by  those  of  ammonia. 
Articles  to  be  vulcanized  by  these  methods  must  be  thin,  since  otherwise 
the  liquids  do  not  penetrate.  Cold  vulcanization  usually  results  in  soft, 
velvet-like  surfaces,  but  articles  treated  by  this  method  are  not  always 
durable. 

PHYSICAL  AND  CHEMICAL  PROPERTIES  OF  RUBBER. 

— Crude  rubber  is  tough,  pliable,  impermeable  to  water  and 
gases,  and  a  very  poor  conductor  of  electricity.  Its  most  char- 
acteristic property  is  elasticity;  that  is,  its  ability  to  return  to 


432  ORGANIC  STRUCTURAL  MATERIALS 

about  its  original  dimensions  after  it  has  been  stretched  through 
a  distance  many  times  its  original  length. 

The  base  of  crude  rubber  is  chemically  Pure  Rubber,  which, 
in  many  places,  is  distinguished  by  the  name  Caoutchouc.  It 
should  be  noted  that  the  name  Caoutchouc  has  two  meanings. 
First,  as  already  stated,  the  meaning  is  frequently  restricted  to 
chemically  pure  rubber;  but,  second,  it  is  also  used  as  a  synonym 
for  crude  rubber;  that  is,  for  pure  rubber  with  its  associated 
compounds.  The  formula  of  pure  rubber,  or  Caoutchouc, 
CioHie,  is  so  approximate  and  general  as  to  be  of  little  use.  The 
same  formula  applies  to  gutta  percha. 

Besides  Caoutchouc,  crude  rubber  contains  resins,  the  functions  of 
which  are  not  understood,  although  it  is  probable  that  they  exert  an 
influence  upon  vulcanization.  Nitrogenous  substances,  proteins,  and 
peptones,  the  functions  of  which,  like  those  of  resins,  have  not  been 
thoroughly  investigated,  are  also  present.  Other  ingredients  may  be 
grouped  as  carbohydrates,  refuse,  such  as  dust  and  bark,  moisture,  and 
materials  or  compounds  introduced  by  coagulating  processes.  It  should 
be  remembered  that  crude  rubber  is,  in  large  part,  a  mixture  containing 
parts  of  practically  all  of  the  constituents  that  existed  in  the  latex  from 
which  the  rubber  was  prepared.  From  this  viewpoint  it  may  be  re- 
garded as,  proportionately,  a  chemical  combination  within  the  mass  of 
which  other  substances  or  compounds  have  become  mechanically  en- 
tangled. Analyses  of  crude  rubber  vary  with  the  character  of  the  latex 
from  which  it  was  prepared,  and  with  the  methods  employed  during  the 
processes  of  coagulation. 

REFERENCES. — "Der  Kautschuk  und  Seine  Prtifung,"  Hinrichsen  and 
Memmler  (Leipzig,  Hirsel,  1910);  "Synthetic  Caoutchouc,  A  Review  Com- 
piled from  the  Literature,"  Barrows  (The  Chemical  Engineer,  September, 
1911,  p.  355);  "Production  and  Polymerization  of  Butadiene,  Isoprene  and 
their  Homologues,"  W.  H.  Perkin,  Jr.  (Journal  Society  Chemical  Industry, 
Vol.  31,  p.  616,  1912);  "Les  Produits  pour  le  Fabrication  du  Caoutchouc 
Synthetique,"  Ditmar  ("Le  Caoutchouc  et  la  Gutta  Percha,"  Paris,  Vol.  IX, 
p.  6458,  1912);  "Les  Caoutchoucs  Artificiels,"  L.  Ventou-Duclax  (Dunot 
and  Pinat,  Paris,  1912);  "Die  Synthese  des  Kautschuks,"  Ditmar  (Theo. 
Steinkopff,  Dresden  and  Leipzig,  1912);  "The  Business  Aspect  of  Synthetic 
Rubber,"  Hinrichsen  (Scientific  American,  August  3,  1912,  p.  99);  "Chem- 
istry of  the  Rubber  Industry,"  Potts  (Constable  and  Company,  London, 
1912);  "Natural  and  Synthetic  Rubber,"  F.  M.  Perkin  (Journal  Royal 
Society  Arts,  London,  Vol.  61,  p.  86,  1913);  "Review  of  Pioneer  Work  on 
Synthesis  of  Rubber,"  Pond  (Journal  American  Chemical  Society,  January, 
1914,  p.  165);  "The  Chemistry  of  Rubber,"  Porritt  (D.  Van  Nostrand 
Company,  New  York,  1915). 


INDIARUBBER  433 

Crude  rubber  is  influenced  by  moderate  changes  in  tempera- 
ture. Heat  causes  it  to  soften  and  become  more  or  less  sticky 
or  " tacky";  sheets  submitted  to  higher  heat  in  dry-rooms  de- 
signed to  dissipate  moisture  absorbed  during  cleansing  some- 
times soften  so  greatly  that  they  drop  from  the  supports  upon 
which  they  are  hung.  Crude  rubber  loses  most  of  its  elasticity 
when  placed  in  boiling  water,  but  hardens  and  becomes  elastic 
again  as  soon  as  it  is  allowed  to  cool.  It  melts  at  about  250 
degrees  F.  and  becomes  a  viscous  fluid  that  does  not  harden  again; 
while  higher  temperatures  cause  decomposition  with  the  forma- 
tion of  various  liquid  hydrocarbons.  It  is  sensitive  to  low  tem- 
peratures; and,  when  subjected  to  excessively  low  tempera- 
tures such  as  those  caused  by  liquid  air,  it  loses  all  elasticity  and 
may  then  even  be  powdered. 

Crude  rubber  is  insoluble  in  water  and  alcohol,  and  is  but 
slightly  acted  upon  by  dilute  acids.  The  effect  of  dilute  alkaline 
solutions  is,  however,  quite  pronounced.  Such  solutions  exert 
a  marked  depolymerizing  action  upon  the  rubber,  which  becomes 
much  softer,  and  if  the  subjection  to  the  alkaline  solution  is 
excessive,  stickiness  and  tackiness  may  result.  Crude  rubber 
is  soluble  in  turpentine,  petroleum  spirits,  carbon  disulphide, 
carbon  tetrachloride,  and  some  other  liquids  the  comparative 
importance  of  which  is  much  in  the  order  mentioned.  These 
liquids  are  used,  either  alone  or  in  mixtures,  whenever  it  is 
necessary  to  dissolve  rubber. 

Crude  rubber  is  subject  to  oxidation,  which  causes  it  first  to 
become  soft,  and  then  to  become  hard,  brittle,  and  useless. 
This  phenomenon,  which  is  technically  known  as  "  perishing," 
is  thought  to  be  influenced  by  light,  heat,  and  the  constituents 
of  the  rubber  itself.  Under  certain  conditions,  vulcanized  rubber 
behaves  in  a  similar  manner,  but  in  such  cases  the  changes  are 
possibly  influenced  to  some  extent  by  fillers  employed  to  secure 
certain  physical  characteristics. 

Crude  rubber  responds  to  the  influence  of  certain  chemical 
substances.  The  changes  that  take  place  when  rubber  is  joined 
with  sulphur  in  vulcanization  have  been  noted.  These  changes 
are  of  a  chemical  nature.  As  distinct  from  these  changes,  how- 
ever, crude  rubber  is  able  to  take  up,  more  or  less  mechanically, 
certain  powders,  such  as  litharge,  powdered  coal,  and  the  salts 
of  aluminum  and  of  iron,  and  to  form  with  them  homogeneous 


434  ORGANIC  STRUCTURAL  MATERIALS 

masses  with  colors  and  other  properties  influenced  correspond- 
ingly by  the  character  of  the  fillers  used. 

Some  of  the  more  characteristic  mixing  ingredients  and  fillers 
are  as  follows:1  Vulcanizing  Agents;  sulphur  and  sulphur 
chloride.  A  ccelerators  of  Vulcanization;  litharge,  calcium  hydrate, 
magnesium  oxide  or  carbonate.  Colorless  Fillers;  whiting,  ba- 
rium sulphate,  lithopone,  French  chalk,  and  zinc  oxide.  Colored 
Fillers;  antimony,  arsenic  or  mercuric  sulphides,  red  lead,  lead 
peroxide,  ferric  oxide,  chromic  oxide,  lead  chromate  (cold  cure), 
ultramarine,  Prussian  blue  (cold  cure),  graphite,  and  lamp-black. 
Organic  Fillers;  paraffin  wax,  pitch,  rosin,  tar,  and  rubber  sub- 
stitutes (white  and  brown). 

From  a  chemical  viewpoint,  vulcanized  rubber  is  principally 
distinguished  from  crude  rubber  by  being  cleaner,  as  well  as  by 
the  presence  of  sulphur  and  of  fillers  used  to  influence  physical 
properties  and  give  colors  to  final  products.  From  the  physical 
viewpoint,  vulcanized  rubber  is  much  more  stable  than  crude  or 
pure  rubber.  It  is  not  influenced  by  moderate  changes  in  tem- 
perature, and  is  more  elastic  and  in  every  way  better  than  crude 
rubber.  The  improvement  caused  by  vulcanizing  is  so  great  that 
practically  all  rubber  is  now  subjected  to  this  process.  Vul- 
canized rubber  may  be  soft  or  hard. 

Soft  vulcanized  rubber,  which  is  obtained  by  limiting  the 
quantity  of  sulphur  and  by  using  comparatively  little  heat,  is 
used  for  such  articles  as  pencil  erasers  and  tubing.  Hard  vul- 
canized rubber,  obtained  by  using  larger  proportions  of  sulphur 
and  higher  degrees  of  heat,  is  called  "  vulcanite"  and  " ebonite." 
This  product  resembles  horn  or  celluloid  and  is  used  for  such 
articles  as  combs  and  buttons.  The  name  "  semi- vulcanite " 
is  sometimes  applied  to  products  that  stand  between  these 
extremes. 

THE  USES  OF  RUBBER. — Rubber  is  used  in  flooring,  auto- 
mobile tires,  belts,  and  machine  foundations.  In  electrical 
science,  it  is  used  as  an  insulating  material;  while  its  value  as  a 
waterproofing  agent  is  of  fundamental  importance.  It  also 
enters  into  hose,  surgical  goods,  sporting  goods,  cements  and  other 
groups  of  articles  and  compounds.  For  many  purposes  satis- 
factory substitutes  for  rubber  do  not  exist. 


1  See  "Chemistry  of  Rubber,"  Porritt  (p.  42). 


INDIARUBBER  435 

Synthetic  Rubber 

Synthetic  rubber  is  the  result  of  a  purely  chemical  process. 
In  composition  and  in  properties  it  is  equivalent  to,  or  the  same 
as,  natural  rubber.  Thus  far  synthetic  rubber  is  a  scientific  truth 
rather  than  a  practical  success.  The  fact  that  artificial  rubber 
can  be  prepared  in  laboratories,  and  that  such  rubber  is  practi- 
cally identical  with  that  obtained  from  trees,  is  beyond  question; 
but  the  cost  of  such  rubber  is  yet  so  high  that  very  little  of  it  is 
manufactured . 

The  ultimate  value  of  synthetic  rubber  must  obviousty  depend 
upon  its  cost  and  quality.  Assuming  the  quality  to  be  satisfac- 
tory, methods  will  have  to  be  devised  whereby  parent  substances 
can  be  prepared  in  larger  quantities  and  more  cheaply  than  at 
present.  The  problem  is  complicated  by  the  fact  that,  with 
present  knowledge,  it  seems  necessary  that  parent  substances 
should  be  particularly  pure. 

It  has  long  been  known  that  an  intimate  relationship  exists  between 
indiarubber  and  a  group  of  substances,  of  which  isoprene  and  butadiene 
are  at  present  the  most  notable.  In  1860,  Williams  isolated  what  is 
now  known  as  isoprene,  from  products  obtained  from  the  destructive 
distillation  of  rubber.  In  1875,  Bouchardat  suggested  that  under  cer- 
tain conditions  isoprene  might  be  converted  back  again  into  rubber.  In 
1892,  Tilden  discovered  that  some  old  specimens  of  isoprene  obtained 
from  turpentine  had  converted  themselves  into  rubber  without  assist- 
ance; and,  in  1909,  Hofmann  and  others  suggested  the  methods  that 
are  now  employed. 

Isoprene  is  obtained  in  several  ways,  as  from  fusil  oil,  and  by  condens- 
ing vapors  of  turpentine  over  iron  at  temperatures  of  from  55°  degrees 
C.  to  600  degrees  C.  (English  patent  27908  of  1909).  Butadiene  is  also 
obtained  in  several  ways,  as  from  products  obtained  by  fermenting  the 
dried  pulp  of  potatoes  (Detoeuf,  Nature,  1912,  p.  306).  Of  the  two 
parent  substances  mentioned,  isoprene  is  a  colorless  liquid-hydrocarbon 
in  which  the  hydrogen  and  carbon  exist  in  the  same  proportions  as  in 
ordinary  rubber.  The  transformation  of  isoprene  to  rubber  is  obtained 
by  placing  isoprene,  selected  for  its  purity,  under  pressure,  and  then 
heating  it,  with  or  without  the  intervention  of  other  substances.  Or 
else,  it  is  transformed  by  the  influence  of  small  quantities  of  other  sub- 
stances, as  metallic  sodium.1 

1  Such  a  change  is  due  to  polymerization,  which  has  been  denned  as  the 
apparent  fusion  or  union  of  two  or  more  molecules,  into  a  more  complex 
molecule  with  a  higher  molecular  weight  and  somewhat  different  physical 
and  chemical  properties  (Century  Dictionary). 


BIBLIOGRAPHY 


INTRODUCTION,  CHAPTERS  I  AND  II 

Conservation.  General. — "  Conservation  Natural  Resources  of  the  United 
States,"  Van  Hise  (The  Macmillan  Company,  1910);  "Conservation  of 
Water  by  Storage,"  Swain  (Yale  University  Press,  1915);  Files  of  Engineer- 
ing News,  Engineering  Record,  American  Forestry;  Transactions  American 
Society  of  Civil  Engineers;  etc.,  etc. 


Botanies.  Anatomy  and  Physiology  of  Trees. — "Principles  of  Botany," 
Bergen  and  Davis  (Ginn  &  Company);  "A  Practical  Course  in  Botany," 
Andrews  (American  Book  Company,  1911);  "Plants,"  Coulter  (D.  Apple- 
ton  &  Company) ;  "  Outlines  of  Botany,"  Leavitt  (American  Book  Company) ; 
"Practical  Botany,"  Bower  (The  Macmillan  Company);  "Manual  of 
Botany,"  Gray  (Seventh  Edition);  "Plant  Anatomy,"  Stevens  (P.  Blakis- 
ton's  Son  &  Company);  "Plant  Physiology,"  Jost  (Gibson,  Oxford,  1907); 
"Textbook  of  Botany,"  Strasburger;  "Forestry  for  Farmers,"  Fernow 
(United  States  Forest  Service,  Farmers  Bulletin  No.  67);  "First  Book  of 
Forestry,"  Roth;  "Manual  of  Trees  of  North  America,"  Sargent;  "Hand- 
book of  Trees  of  the  Northern  States  and  Canada,"  Hough;  "Silva  of  North 
America,"  Sargent;  "Cyclopedia  of  American  Horticulture,"  Bailey; 
"North  American  Trees,"  Britton  and  Shafer;  Files  of  Botanical  Gazette; 
Files  of  American  Forestry;  Files  of  Forestry  Quarterly;  etc.,  etc. 


Forestry. — "Forestry  for  Farmers,"  Fernow  (United  States  Forest 
Service,  Farmers  Bulletin  No.  67);  "First  Book  of  Forestry,"  Roth  (Ginn  & 
Company,  1902);  "Practical  Forestry,"  Gifford  (D.  Appleton  &  Company, 
1903);  "Primer  of  Forestry,"  Pinchot;  "Conservation  of  Natural  Resources 
in  the  United  States,"  Van  Hise  (The  Macmillan  Company);  Files  of 
American  Forestry  and  Forestry  Quarterly;  Publications  of  United  States 
Forest  Service;  "Histology  of  Medicinal  Plants,"  Mansfield  (John  Wiley 
&  Sons,  1917),  etc. 


1  The  names  "Division  of  Forestry"  and  "Bureau  of  Forestry " have  been 
used  by  the  National  Government  to  denote  what  is  now  its  "Forest 
Service." 

437 


438  ORGANIC  STRUCTURAL  MATERIALS 


CHAPTER  III 

Identifications. — Cellular  Structure  of  Wood.  Character  and  Arrange- 
ment of  Wood-elements.  "Structure  of  Certain  Timber  Ties,  etc.," 
Dudley  (United  States  Forest  Service,  Bulletin  No.  1);  " Timber, "Roth 
(United  States  Forest  Service,  Bulletin  No.  10);  "The  Decay  of  Timber," 
von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin  No.  14, 
p.  12);  Tiemann  (Trans.  American  Railway  Engineering  Association,  Bul- 
letins No.  107  and  No.  120);  "North  American  Gymnosperms,"  Penhallow; 
"Outlines  of  Botany,"  Leavitt  (American  Book  Company);  "Materials  of 
Construction,"  Johnson;  "Plant  Anatomy,"  Stevens  (P.  Blakiston's  Son 
&  Company);  "Wood,"  Boulger  (London,  Second  Edition);  "Pithray  Flecks 
in  Wood,"  Brown  (United  States  Forest  Service,  Circular  No.  215);  "Resin 
Canals  in  White  Fir,"  Mell  (American  Forestry,  June,  1910);  "Textbook 
of  Botany,"  Strasburger;  "Chemistry  and  Physics  of  Building  Materials," 
Munby;  "  Identification  of  Important  American  Oak  Woods,"  Sud worth  and 
Mell  (United  States  Forest  Service,  Bulletin  No.  102);  "  Confusion /of 
Technical  Terms  in  Study  of  Wood  Structure,"  Mell  (Forestry  Quarterly, 
Vol.  IX,  1911,  No.  4);  "Identification  of  Economic  Woods  of  United 
States,"  Record  (John  Wiley  &  Sons,  1912). 

CHAPTER  IV 

The  Trunk:  Bark,  Sapwood  and  Heartwood,  Annual  Layers,  Imperfec- 
tions.— "Plant  Anatomy,"  Stevens  (P.  Blakiston's  Son  &  Company, 
1910);  "Plant  Physiology,"  Jost  (Oxford  Press,  1907);  "Age  of  Trees  and 
Time  of  Blazing  Determined  by  Annual  Rings,"  Fernow  (United  States 
Division  of  Forestry,  Circular  No.  16,  pp.  2,  3  and  6);  "Rules  and  Specifica- 
tions for  the  Grading  of  Lumber  Adopted  by  the  Various  Manufacturing 
Associations  of  the  United  States, "  (United  States  Forest  Service,  Bulletin 
No.  71). 

CHAPTERS  V,  VI,  VII,  VIII 

Nomenclature.  Localities. — "Check  List  of  Forest  Trees  of  the  United 
States,"  Sud  worth  (United  States  Forest  Service,  Bulletin  No.  17);  "Man- 
ual of  the  Trees  of  North  America,"  Sargent  (Houghton,  Mifflin  &  Com- 
pany); "Wood,"  Boulger  (Edward  Arnold,  London,  Second  Edition);  "Die 
Pflanzengattungen,  Geographische  Verbreitung,  Anzahl  und  Verwandschaft 
aller  bekannten  Arten  und  Gattungen  im  Pflanzenreich,"  J.  C.  T.  Uphof 
(Leipzig,  1910). 

Descriptions  of  Trees. — "Silva  of  North  America,"  Sargent;  Vol.  IX, 
Tenth  United  States  Census;  "Cyclopedia  of  American  Horticulture," 
Bailey  and  Miller;  "Illustrated  Flora  of  the  Northern  United  States,  Can- 
ada, and  the  British  Possessions,"  Britton  and  Brown  (1896-98);  "Manual 
of  the  Trees  of  North  America  Exclusive  of  Mexico,"  Sargent;  "Handbook  of 
the  Trees  of  the  Northern  States  and  Canada,"  Hough;  "The  Foresters' 
Manual,"  Ernest  Thompson  Seton;  Publications  of  the  United  States  Forest 
Service  and  other  Bureaus  of  the  United  States  Department  of  Agriculture. 


BIBLIOGRAPHY  439 

Descriptions  of  Woods.  Structural  Qualities. — "Silva  of  North  Amer- 
ica," Sargent;  " American  Woods"  (actual  sections),  Hough;  Jesup  Collec- 
tion of  Woods  at  Museum  of  Natural  History,  New  York  City;  Vol.  IX, 
Tenth  United  States  Census;  " Inspection  of  Materials  and  Workmanship," 
Part  1,  Kidder;  "The  Materials  of  Construction,"  Johnson;  "Timber  and 
Timber  Trees,"  Laslett  (London);  "Timbers  of  Commerce,"  Stone  (London); 
Report  on  Forests  of  Western  Australia,"  J.  Ednie  Brown;  Publications 
Baron  Ferd.  von  Mueller;  "Important  Philippine  Woods,"  Captain  Ahern,  IT. 
S.  A.;  "Wood,"  Boulger  (Second  Edition,  London);  "American  Lumber  in 
Foreign  Markets"  (Special  Consular  Reports,  Vol.  XI,  United  States  State  De- 
partment); Publications  of  American  Railway  Engineering  Association;  Files 
of  Engineering  News;  Files  of  Engineering  Record;  Proceedings  of  American 
Society  for  Testing  Materials;  Publications  of  the  United  States  Forest  Ser- 
vice and  other  Bureaus  of  the  United  States  Department  of  Agriculture, 
(specific  documents  are  mentioned  in  connection  with  the  woods  described) ; 
"Mechanical  Properties  of  Wood,"  Record  (John  Wiley  &  Sons,  1914);  see 
also  list  under  "Physical  Properties  of  Woods." 

Uses  of  Wood. — "Catalogue  of  the  Jesup  Collection,"  Sargent;  Files  of 
American  Lumberman  (Chicago),  The  Lumber  Trade  Journal  (New  Or- 
leans), The  New  York  Lumber  Trade  Journal,  The  Southern  Lumberman 
(Nashville,  Tenn.),  The  Lumber  World  Review  (Chicago),  The  Hardwood 
Record  (Chicago),  American  Forestry,  Engineering  News  and  Engineering 
Record;  Publications  American  Railway  Engineering  Association;  Proc. 
American  Society  for  Testing  Materials;  Vol.  IX,  Tenth  United  States  Cen- 
sus; "Uses  of  Wood,"  Roth  (Department  of  Agriculture  Yearbook,  1896); 
"A  Study  of  the  Wisconsin  Wood-using  Industries,"  Smith  (Published  State 
Department  of  Forestry,  Madison,  Wis.);  "The  Wood-using  Industries  of 
Illinois,"  Simmons  (Published  Department  of  Horticulture,  University  of 
Illinois);  "The  Wood-using  Industries  of  Maryland,"  Maxwell  (Published 
Maryland  State  Board  of  Forestry);  "Forest  Products  of  the  United  States" 
(Bureau  of  Census,  1909);  Publications  Office  of  Wood  Utilization  (United 
States  Forest  Service) ;  Other  publications  of  the  United  States  Department 
of  Agriculture;  specific  documents  are  mentioned  in  connection  with  the 
woods  described. 

CHAPTER  IX 

Physiological,  Chemical,  and  Physical  Properties  of  Woods. — "Physio- 
logical Roll  of  Mineral  Nutrients,"  Loew  (United  States  Division  Vegetable 
Physiology  and  Pathology,  Bulletin  No.  18,  1899);  "Plant  Physiology," 
Jost  (Gibson,  Oxford,  1907);  United  States  Dispensatory;  " Microchemistry 
of  Plant  Products,"  Stevens  (Plant  Anatomy,  pp.  330-367);  "Sap  in  Rela- 
tion to  the  Properties  of  Woods,"  Record  (Proc.  American  Wood  Preservers 
Association,  Baltimore,  Md.,  1913,  pp.  160-166);  Vol.  IX,  Tenth  United 
States  Census;  Executive  Document  No.  5,  Forty-eighth  Congress,  First 
Session;  "Applied  Mechanics,"  Lanza;  "Materials  of  Construction,"  John- 
son; "Timber  Physics,  Part  1,  Preliminary  Report"  (United  States  Forest 
Service,  Bulletin  No.  6,  1892);  "Timber  Physics,  Part  2,  Progress  Report" 
(United  States  Forest  Service,  Bulletin  No.  8,  1893);  "Report  on  Preserva- 


440  ORGANIC  STRUCTURAL  MATERIALS 

tive  Processes  and  Metal  Tie  Plates  for  Wooden  Ties,"  Tratman  (United 
States  Division  of  Forestry,  1894);  "  Timber,"  Roth  (United  States  Forest 
Service,  Bulletin  No.  10,  1895);  "  Southern  Pine — Mechanical  and  Physical 
Properties"  (United  States  Forest  Service,  Circular  No.  12,  1896);" Timber 
Pines  of  the  Southern  United  States"  (United  States  Forest  Service,  Bulletin 
No.  13,  1897);  "Summary  of  Mechanical  Tests  on  Thirty-two  Species  of 
American  Woods"  (United  States  Forest  Service,  Circular  No.  15,  1897); 
"The  Efficiency  of  Built-up  Wooden  Beams,"  Kidwell  (Trans.  American 
Institute  of  Mining  Engineers,"  July,  1897);  "American  Railway  Bridges 
and  Buildings,"  Berg  (Proceedings  of  the  Association  of  Railway  Superin- 
tendents of  Bridges  and  Buildings,  1898);  "Economical  Designing  of  Timber 
Trestle  Bridges,"  Johnson  (United  States  Forest  Service,  Bulletin  No.  12, 
1902);  "Tests  on  the  Physical  Properties  of  Timber,"  Olmsted  (United 
States  Department  of  Agriculture  Yearbook,  1902);  Transactions  of  the 
American  Society  of  Civil  Engineers,  (Vol.  LI,  1903);  "Progress  Report  on 
the  Strength  of  Structural  Timber,"  Hatt  (United  States  Forest  Service, 
Circular  No.  32,  1904);  "Cross  Tie  Forms  and  Rail  Fastenings  with  Special 
Reference  to  Treated  Timbers,"  von  Schrenk  (United  States  Bureau  of  For- 
estry, Bulletin  No.  50,  1904);  "Instructions  to  Engineers  of  Timber  Tests," 
Hatt  (United  States  Forest  Service,  Circular  No.  38,  1906);  "Experiments 
on  the  Strength  of  Treated  Timber,"  Hatt  (United  States  Forest  Service, 
Circular  No.  39,  1906);  "Holding  Force  of  Railroad  Spikes  in  Wooden  Ties," 
Hatt  (United  States  Forest  Service,  Circular  No.  46,  1906);  "The  Red 
Gum,"  Chittenden  (United  States  Forest  Service,  Bulletin  No.  58,  1906); 
"Effect  of  Moisture  upon  the  Strength  and  Stiffness  of  Wood,"  Tiemann 
(United  States  Forest  Service,  Bulletin  No.  70,  1906);"  The  Strength  of 
Wood  as  Influenced  by  Moisture,"  Tiemann  (United  States  Forest  Service, 
Circular  No.  108,  1907);  "Second  Progress  Report  on  the  Strength  of 
Structural  Timber,"  Hatt  (United  States  Forest  Service,  Circular  No.  115, 
1907);  "Organization,  Equipment,  and  Operation  of  the  Structural  Mater- 
ials, Testing  Laboratories  at  St.  Louis,  Missouri,"  Humphreys  (United 
States  Geological  Survey,  Bulletin  No.  329,  1908);  "Tests  of  Vehicle  and 
Implement  Woods"  (United  States  Forest  Service,  Circular  No.  142, 
1908);  Tests  of  Timber  Beams,"  Talbot  (University  of  Illinois,  Bulletin 
No.  41,  1909);  "Properties  and  Uses  of  Southern  Pines,"  (United  States 
Forest  Service,  Circular  No.  164,  1909);  "The  Commercial  Hickories" 
(United  States  Forest  Service,  Bulletin  No.  80,  1910);  "Utilization  of 
California  Eucalyptus"  (United  States  Forest  Service,  Circular  No.  179, 
1910);  "Properties  and  Uses  of  Douglas  Fir"  (United  States  Forest 
Service,  Bulletin  No.  88,  1911);  "Strength  Values  for  Structural  Timbers," 
Cline  (United  States  Forest  Service,  Circular  No.  189,  1912);  Bulletins 
American  Railway  Engineering  Association;  Proceedings  American  Society 
for  Testing  Materials,  etc.;  "Mechanical  Properties  of  Wood,"  Record 
(John  Wiley  &  Sons,  1914). 


BIBLIOGRAPHY  441 


CHAPTER  X 

Fungi  and  Fungous  Diseases  of  Woods. — "Outlines  of  Botany,"  Leavitt; 
"Fungous  Diseases  of  Plants,"  Duggar;  "Diseases  of  Economic  Plants," 
Stevens  and  Hall;  "Flowerless  Plants,"  Bennett  (Published  Gurney  & 
Jackson,  London);  "Fungous  Diseases  of  our  Forest  Trees,"  Halstead 
(Third  Annual  Report  Pennsylvania  Department  of  Agriculture);  "Diseases 
of  Trees,"  Hartig;  "Diseases  of  Plants  Induced  by  Cryptogamic  Parasites," 
Tubeuf  and  Smith;  "Studies  of  Some  Shade  Tree  and  Timber  Destroying 
Fungi,"  Atkinson  (Cornell  Exper.  Sta.,  Bulletin,  No.  193) ;  Bulletins  American 
Railway  Engineering  Association;  " Disease  of  Taxodium  known  as  Pecki- 
ness,"  von  Schrenk  (Contribution  14,  Shaw  School  of  Botany);  "Decay  of 
Timber,"  von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin 
No.  14);  "Two  Diseases  of  Red  Cedar,"  von  Schrenk  (United  States  Divi- 
sion Vegetable  Physiology  and  Pathology,  Bulletin  No.  21);  "Fungous 
Diseases  of  Forest  Trees,"  von  Schrenk  (United  States  Department  of 
Agriculture  Yearbook,  1900);  "Some  Diseases  of  New  England  Conifers" 
(United  States  Division  Vegetable  Physiology  and  Pathology,  Bulletin  No. 
25);  "Diseases  of  White  Ash,"  von  Schrenk  (United  States  Bureau  Plant 
Industry,  Bulletin  No.  32);  "Diseases  of  Bull  Pine,"  von  Schrenk  (United 
States  Bureau  Plant  Industry,  Bulletin  No.  36);  "Diseases  of  Hardy 
Ca.talpa,"  von  Schrenk  (United  States  Bureau  of  Forestry,  Bulletin  No.  37); 
"The  Discovery  of  Cancer  in  Plants;  An  Account  of  Some  Experiments  by 
the  United  States  Department  of  Agriculture,"  (The  National  Geographic 
Magazine,  Vol.  XXIV,  No.  1,  1913);  "Preservation  of  Structural  Timber," 
Weiss  (McGraw-Hill  Book  Company,  1915);  "Diseases  of  Deciduous  Forest 
Trees,"  von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin 
No.  149,  which  also  contains  extensive  bibliography),  etc. 


CHAPTER  XI 

Failure  of  Wood  because  of  Fire.  Fire  Protection. — "On  the  Compara- 
tive Value  of  Certain  Salts  for  Rendering  Fibrous  Substances  Non-inflam- 
mable," Versmann  and  Oppenheim  (British  Association  for  the  Advance- 
ment of  Science,  Report  of  the  29th  Meeting  held  at  Aberdeen,  September, 
1859.  Notices  and  Abstracts,  pp.  86-88,  1859);  "Rapport  sur  les  pro- 
cedes  destines  a  assurer  Pinflammabilite  des  bois,"  Boudin  and  Donny 
(Annales  de  1' Association  des  Ingenieurs  sortis  des  Ecoles  Speciales  de 
Gand.,  Belgium,  Vol.  2,  p.  1,  1887);  "Fire  Protection  of  Mills,"  Woodbury 
(John  Wiley  &  Sons,  1895);  "Contributions  of  Chemistry  to  the  Methods  of 
Preventing  and  Extinguishing  Conflagrations,"  Norton  (Journal  of  Ameri- 
can Chemical  Society,  Vol.  XVII,  1895);  Publications  of  National  Board 
of  Fire  Underwriters;  Publications  National  Fire  Protection  Association; 
Files  of  Insurance  Engineering;  "  Process  of  Fireproofing  Wood  for  the  Wood- 
work of  Warships,"  Hexamer  (Engineering  News,  March  23,  1899);  "A 
Discussion  of  Recent  Developments  in  the  Fireproofing  of  Wood,"  Ferrell 
(Journal  of  Franklin  Institute,  March,  1901);  "A  New  Method  of  Testing 
Fire-resisting  Qualities  of  Fire-proofed  Wood,"  Woolsen  (Engineering  News, 


442  ORGANIC  STRUCTURAL  MATERIALS 

February  20,  1902);  " Insurance  in  Foreign  Countries"  (United  States 
Special  Consular  Report,  Vol.  38,  Bureau  of  Manufactures,  Department  of 
Commerce  and  Labor,  Washington,  1905);  "A  New  Investigation  of  the 
Fireproofing  of  Fabrics,"  Whipple  and  Fay  (Part  of  "The  Safeguarding 
of  Life  in  Theatres,"  Freeman,  Transactions  of  American  Society  of  Mechan- 
ical Engineers,  Vol.  27,  1906);  "The  Safeguarding  of  Life  in  Theatres," 
Freeman  (Transactions  of  American  Society  of  Mechanical  Engineers,  Vol. 
27,  1906);  "Waste  of  our  National  Resources  by  Fire,"  Baker  (Proceedings 
of  Meeting  called  jointly  by  the  American  Society  of  Civil  Engineers,  the 
American  Institute  of  Mining  Engineers,  the  American  Society  of  Mechan- 
ical Engineers,  and  the  American  Institute  of  Electrical  Engineers,  published 
in  pamphlet,  1909);  "The  Fire-resistive  Properties  of  Various  Building 
Materials,"  Humphrey  (United  States  Geological  Survey,  Bulletin  No.  370, 
1909);  "The  Fire  Tax  and  Waste  of  Structural  Materials  in  the  United 
States,"  Wilson  and  Cochrane  (United  States  Geological  Survey,  Bulletin 
No.  418,  1910);  "The  Enormous  Fire  Waste  of  the  United  States,"  Cochrane 
(Scientific  American,  June  15,  1912);  "Fire  Prevention  and  Fire  Protec- 
tion," Freitag  (John  Wiley  &  Sons,  1912);  "The  Modern  Factory,"  Price 
(John  Wiley  &  Sons,  1914) ;  "Tests  on  Inflammability  of  Untreated  Wood  and 
of  Wood  Treated  with  Fire-retarding  Compounds,"  Prince  (Report  on  Uses 
of  Wood,  National  Fire  Protection  Association,  1915). 

CHAPTER  XII 

Marine  and  Terrestrial  Woodborers. — "Marine  Woodborers,"  Snow 
(Transactions  of  the  American  Society  of  Civil  Engineers,  Vol.  XI,  1898); 
Sigerfoos  (Circular,  Johns  Hopkins  University,  June,  1896);  Harriet 
Richardson  (Biological  Society,  Washington,  May,  1897);  "Insect  Life," 
Comstock  (Appleton);  "Guide  to  the  Study  of  Insects,"  Packard  (Holt, 
Ninth  Edition);  The  Fifth  Report  of  the  United  States  Entomological 
Commission;  "Insects  Affecting  Park  and  Woodland  Trees,"  Felt  (New 
York  State  Museum,  1906);  "The  White  Ant,"  Marlatt  (United  States 
Division  of  Entomology,  Circular  No.  50,  New  Series);  "The  Insect  Book," 
Howard  (Doubleday,  Page  &  Company,  1910);  "Insect  Injuries  to  Forest 
Products,"  Hopkins  (United  States  Bureau  of  Entomology,  Circular  No. 
128,  1910);  "Report  on  the  Field  Work  Against  the  Gypsy  Moth  and  the 
Brown-tail  Moth,"  Rogers  and  Burgess  (United  States  Bureau  of  Ento- 
mology, Bulletin  No.  87,  1910);  "Some  Insects  Injurious  to  Forests/' 
Hopkins  and  Webb  (United  States  Bureau  of  Entomology,  Bulletin  No.  58, 
1910);  "A  List  of  Works  on  North  American  Entomology,"  Banks  (United 
States  Bureau  of  Entomology,  Bulletin  No.  81,  1910);  "Injurious  Insects 
and  How  to  Recognize  and  Control  Them,"  O'Kane  (The  Macmillan  Com- 
pany); "List  of  Publications  Relating  to  Forest  Insects,"  Hopkins  and 
Others  (United  States  Bureau  of  Entomology,  Bulletin  No.  58,  pp.  96-101, 
1910);  "Practical  Entomology  for  Schools,"  Sanderson  and  Pearirs  (John 
Wiley  &  Sons,  1917). 


BIBLIOGRAPHY  443 

CHAPTER  XIII 

Wood  Seasoning. — "Timber,"  Roth  (United  States  Division  of  Forestry, 
Bulletin  No.  10,  1895);  "Seasoning  of  Timber,"  von  Schrenk  (United  States 
Bureau  of  Forestry,  Bulletin  No.  41,  1903);  "  Kiln-drying  Hardwood  Lum- 
ber," Dunlap  (United  States  Forest  Service,  Circular  No.  48,  1906);  "Prin- 
ciples of  Drying  Lumber  at  Atmospheric  Pressure,"  Tiemann  (United  States 
Forest  Service,  Bulletin  No.  104,  1912);  "Preservation  of  Structural  Tim- 
ber," Weiss  (McGraw-Hill  Book  Company,  1915);  also  see  catalogues  of 
the  B.  F.  Sturtevant  Company,  the  Morton  Dry  Kiln  Company,  the  Stand- 
ard Dry  Kiln  Company,  the  American  Blower  Company,  etc.  "The 
Theory  of  Drying,  etc."  Tieman  (United  States  Department  of  Agricul- 
ture, Bulletin  No.  509,  March  17,  1917). 


CHAPTER  XIV 

Wood  Antiseptics :  Their  Application  Within  Woods. — "  Fractional  Dis- 
tillation of  Coal-tar  Creosote,"  Dean  and  Bateman  (United  States  Forest 
Service,  Circular  No.  80);  "Quantity  and  Character  of  Creosote  in  Well- 
preserved  Timbers,"  Alleman  (United  States  Forest  Service,  Circular  No.  98) ; 
"The  Analysis  and  Grading  of  Creosotes"  (United  States  Forest  Service, 
Circular  No.  112);  "Volatilization  of  Various  Fractions  of  Creosote  after 
their  Injection  into  Wood,"  Teesdale  (United  States  Forest  Service,  Cir- 
cular No.  188);  "Modification  of  the  Sulphonation  Test  for  Creosote," 
Bateman  (United  States  Forest  Service,  Circular  No.  191);  "Wood  Preserva- 
tion," Flad  (United  States  Forest  Service,  Bulletin  No.  1,  1887);  "Causes 
Underlying  the  Limited  Production  of  Creosote  in  the  United  States" 
(Forestry  and  Irrigation,  October,  1906,  pp.  482-484);  "Decay  of  Timber," 
von  Schrenk  (United  States  Bureau  of  Plant  Industry,  Bulletin  No.  14); 
"Recent  Progress  in  Timber  Preservation,"  von  Schrenk  (United  States 
Department  of  Agriculture,  Yearbook,  1903);  "Coal-tar  and  Ammonia," 
Lunge;  "Handbook  of  Timber  Preservation,"  Samuel  M.  Rowe  (Author's 
Edition,  1900);  "The  Preservation  of  Structural  Timber,"  Weiss  (McGraw- 
Hill  Book  Company,  1915);  "Antiseptic  Treatment  of  Timber,"  Boulton 
(Proceedings  Institution  of  Civil  Engineers,  London,  1884);  "The  Preserva- 
tion of  Timber,"  Report  of  Committee  (Transactions  American  Society 
of  Civil  Engineers,  1885);  "Preservation  of  Railroad  Ties,"  Curtis  (Trans- 
actions American  Society  of  Civil  Engineers,  Vol.  XLII,  1899);  "Proposed 
Method  of  Preservation  of  Timber  with  Discussion,"  Kummer  (Transac- 
tions American  Society  of  Civil  Engineers,  Vol.  XLIV,  1900);  "Preserva- 
tion of  Railway  Ties  in  Europe,"  Chanute  (Transactions  American  Society 
of  Civil  Engineers,  Vol.  XLV,  1901);  "Timber  Tests  and  Discussions" 
(Transactions  American  Society  of  Civil  Engineers,  Vol.  LI,  1903);  "The 
Inspection  of  Treatment  for  the  Protection  of  Timber  by  the  Injection  of 
Creosote  Oil,"  Stanford  (Transactions  American  Society  of  Civil  Engineers, 
Vol.  LVI,  1905);  Manual,  1911  and  other  publications  of  the  American 
Railway  Engineering  Association;  Specifications  American  Telephone  and 
Telegraph  Company;  Proc.  American  Wood  Preservers  Association;  Proc. 


444  ORGANIC  STRUCTURAL  MATERIALS 

American  Society  of  Municipal  Improvements;  Files  Engineering  News, 
Engineering  Record,  Municipal  Engineering,  etc.  Assistance  was  received 
from  the  Eppinger  &  Russell  Company,  Mr.  H.  M.  Mason,  Jr.  of  that 
Company,  Mr.  John  S.  Crandell  of  the  Barrett  Manufacturing  Company, 
and  others. 

CHAPTER  XV 

Paints,  Varnishes  and  Other  Coatings:  Their  Application  to  Woods. — 
"Painters'  Colours,  Oils,  and  Varnishes,"  Hurst  (London,  1896);  "Drying 
Oils,"  Andes  (Scott,  Greenwood  &  Sons,  London);  "Preparation  and  Uses 
of  White  Paints,"  Fleury  (Scott,  Greenwood  &  Sons,  London);  "White  Lead 
and  Zinc  Paints,"  Petit  (Scott,  Greenwood  &  Sons,  London,  1907);  "Letters 
to  a  Painter,"  Ostwald  (Ginn  &  Company,  Boston,  1907);  "Analysis  of 
Mixed  Paints,"  Holley  &  Ladd  (John  Wiley  &  Sons,  1908);  "Lead  and  Zinc 
Pigments,"  Holley  (John  Wiley  &  Sons,  1909);  "Linseed  Oil,"  Ennis  (Van 
Nostrand,  1910);  "Chemistry  of  Paints,"  Friend  (Longmans,  Green  &  Com- 
pany, 1910);  "Materials  of  the  Painters'  Craft,"  Laurie  (Foulis,  London  and 
Edinburgh,  1910);  "White  Paints  and  Painting  Materials,"  Scott  (Modern 
Painter,  Chicago,  1910);  "Manufacture  of  Varnishes,"  Mclntosh  (Scott, 
Greenwood  &  Sons,  London,  1911);  "Materials  for  Permanent  Painting," 
Toch  (Van  Nostrand,  1911);  "Paint  Technology  and  Tests,"  Gardner 
(McGraw-Hill  Book  Company,  December,  1911);  "The  Analysis  of  Paints 
and  Painting  Materials,"  Gardner  and  Schaeffer  (McGraw-Hill  Book  Com- 
pany); "German and  American  Varnish-Making,"  Bottler  and  Sabin  (John 
Wiley  &  Sons,  1912);  "Technology  of  Paint  and  Varnish,"  Sabin  (John 
Wiley  &  Sons,  1904  and  1917);  "The  China  Wood  Oil  Tree,"  Fairchild 
(United  States  Bureau  of  Plant  Industry,  Circular  No.  108);  "Index  to 
Patents,  Technology,  and  Bibliography  of  China  Wood  Oil  (Tung  Oil)," 
George  H.  Stevens  and  J.  Warren  Armitage  (Published  by  Authors  at 
Irvington  and  Newark,  New  Jersey,  1914);  Files  of  Painters'  Magazine, 
Oil  and  Color  Trades  Journal,  Drugs,  Oils,  and  Paints;  Proceedings  of 
the  Paint  and  Varnish  Society  (London),  Farbenzeitung  (Berlin),  Le  Revue 
de  Chimie  Industrielle  (Paris),  Engineering  News,  Engineering  Record, 
Railway  Gazette,  Transactions  American  Society  for  Testing  Materials, 
Red  Lead  and  How  to  Us;>  It,  Sabin  (Author's  edition,  1917),  Journal  Indus- 
trial and  Engineering  Chemistry  (American  Chemical  Society) .  Assistance 
was  received  from  the  Sherwin-Williams  Company,  the  F.  W.  DeVoe  and 
C.  T.  Raynolds  Company,  the  Dixon  and  the  Detroit  Graphite  Companies, 
the  Heath  and  Milligan  Manufacturing  Company,  etc. 


CHAPTER  XVI 

Adhesives:  Cattle  Glues,  Fish  Glues. — "Glue,  Gelatine,  Isinglass,  Ce- 
ments, and  Pastes,"  Dawidowsky  (Sampson  Low,  Marston,  Searle  & 
Rivington,  London,  1884);  "Glue  and  Glue  Testing,"  Samuel  Rideal  (Scott, 
Greenwood  &  Sons,  London,  1900);  "Glues  and  Gelatine,"  Fernbach  (Van 
Nostrand  Company,  1907);  Files  of  Scientific  American,  Woodcraft,  etc., 
etc.  Assistance  was  received  from  Messrs.  Armour  &  Company,  the  Ameri- 


BIBLIOGRAPHY  445 

can  Glue  Company,  the  Russia  Cement  Company,  the  Studebaker  Corpora- 
tion, Schmitt  Brothers,  The  Flint  &  Homer  Company,  and  other  manu- 
facturers and  users  of  glue. 

CHAPTER  XVII 

Indiarubber:  Its  Sources,  Properties,  and  Uses. — "Crude  Rubber  and 
Compounding  Ingredients,"  Pearson  (Indiarubber  Publishing  Company, 
New  York,  1909);  Files  of  Indiarubber  World,  Journal  of  Society  of 
Chemical  Industry;  "The  Culture  of  the  Central  American  Rubber  Tree," 
Cook  (United  States  Bureau  of  Plant  Industry  Bulletin  No.  49);  "Rubber 
Cultivation  for  Porto  Rico,"  Cook  (United  States  Division  of  Botany, 
Circular  No.  28);  "Indiarubber"  (Special  Consular  Reports,  United  States 
Government  Printing  Office,  1892);  "Guayule,  A  Rubber  Plant  of  the 
Chihuahuan  Desert."  Lloyd  (Carnegie  Institution,  Bulletin  No.  129); 
"Indiarubber  and  Gutta  Percha,"  Seeligmann,  Torrilhon  and  Falconnet 
(Scott,  Greenwood  &  Company,  London,  1910);  "Rubber,"  Schidrowitz 
(Methune  &  Company,  London,  1911) ;  "  Der  Kautschuk  und  Seine  Priifung," 
Hinrichsen  and  Memmler  (Leipzig,  Hirsel  1910);  "Synthetic  Caoutchouc, 
A  Review  Compiled  from  the  Literature,"  Barrows  (The  Chemical  Engi- 
neer, September,  1911,  p.  355);  "Production  and  Polymerization  of  Butad- 
iene, Isoprene  and  their  Homologues,"  W.  H.  Perkin,  Jr.  (Journal  Society 
Chemical  Industry,  Vol.  31,  p.  616,  1912);  "Les  Produits  pour  le  Fabrica- 
tion du  Caoutchouc  Synthetique,"  Ditmar  ("Le  Caoutchouc  et  la  Gutta 
Percha,"  Paris,  Vol.  IX,  p.  6458,  1912);  "Les  Caoutchoucs  Artificiels," 
L.  Ventou-Duclaux  (Dunot  and  Pinat,  Paris,  1912);  "Die  Synthese  des 
Kautschuks,"  Ditmar  (Theo.  Steinkopff,  Dresden  and  Leipzig,  1912); 
"The  Business  Aspect  of  Synthetic  Rubber,"  Hinrichsen  (Scientific  American, 
August  3,  1912,  p.  99);  "Chemistry  of  the  Rubber  Industry,"  Potts  (Con- 
stable and  Company,  London,  1912);  "Natural  and  Synthetic  Rubber," 
F.  M.  Perkin  (Journal  Royal  Society  Arts,  London,  Vol.  61,  p.  86,  1913); 
"Review  of  Pioneer  Work  on  Synthesis  of  Rubber,"  Pond  (Journal  Ameri- 
can Chemical  Society,  January,  1914,  p.  165);  "The  Chemistry  of  Rubber," 
Porritt  (D.  Van  Nostrand  Company,  New  York,  1915).  Assistance  was 
received  from  the  Birmingham  Iron  Foundry,  Mr.  Thomas  A.  Cashman, 
Dr.  Earl  F.  Farnau  of  New  York  University,  and  others. 


INDEX 


PAGE 
269 

PAGE  Algaroba 168 

Abies 65,  72  Allardyce  Process  (Wood  Pres- 

balsamea 72,  73,  169  ervation 371 

concolor .     76  Alligatorwood 188 

grandis 72,  74  Amber . 385,  386 

lowiana 76  Amber,  black 386 

magnified 72,  75  American  Railway  Eng.  Assn. : 

nobilis 72,  77  Spec,  for  Creosote .  .   344,  345,  346 

taxifolia... 70  American    Telephone    &    Tele- 

Abietene 60  graph  Co. : 

Abrasion 241,  256  Spec,  for  Application  of  Creo- 

Resistance  to 241  sote,    358,    359,    360,    365, 

Acacia 166  366,  367,  368,  370 

False 166  Spec,  for  Creosote 346,  347 

Three-thorned 167  Spec,  for  Open  Tank  Process  358, 

Acer 133  359 

dasycarpum 135  Ammonium  phosphate  (fire  re- 

macrophyllum 137  tardant)  ....  282,  283,  284 

negundo 138  Ancona  Auvergne 141 

pseudo-platanus 133,  156  Angiosperms 4, 102,  247 

rubrum 136  Animal  Life,  Woods  Destroyed 

saccharinum 134,135,272  by 225,   300-325,   340 

saccharum 40,  133, 134,  246  Anime 386 

Adhesives,  159,  206,  208,  337,  403,  Annual    Deposit     (see    Annual 

404,    405,    406,    407,    408,  Rings,  Bands  or  Layers). 

409,  410,  411,  412,  413,  414,  Annual  Rings,  Bands  or  Layers,  5,  6, 

415,  416,  417,  418,  419,  420  10, 11,  29,  30,  34,  35,  36,  37, 

Aesculus 183  46,  102,  260 

calif ornica 183,  185  Ant,  Black  Carpenter 323 

flava 185  White 321 

glabra 183,  184  Antiseptic  Treatment  of  Wood,  322, 

hippocastanum 183,184  327,328,329,330,331,335, 

octandra 183,  185  336,  337,  353,  354,  355,  356, 

Agathis  australis 63  357,358,359,360,361,362, 

Age,  Woods  Destroyed  by.   266,  267  363,  364,  365,  366,  367,  368, 

Ailanthus 172  370,  371,  372,  373,  374 

Ailanthus  glandulosa 172  Antiseptics,  Wood,  262,  265,  335,  338, 

Alburnum 37  339,  340,  341,  342,  343,  344, 

Alcohol. . . .   381,  387,  424,  425,  426  345,  346,  347,  348,  349,  350, 

Aleuritesfordii 214,  380  351,  352,  353 

447 


448 


INDEX 


PAGE 

Apple 92,  126, 127,  213 

American  Crab 127 

Narrowleaf  Crab 127 

Oregon  Crab ..  .   127 

Sweet  Crab 127 

Apple-tree 116, 127 

Osage 204 

Arborvitse 85,  86,  89,  90 

Giant 90 

Arbutus 195 

menziesii 195,  197 

texana 197 

xalapensis 197 

Arctostaphylos 197 

glauca 197 

pungens 197 

tomentosa. 197 

Arundinaria 231 

Arundo 231 

Asbestos 284,  285,  401 

Asbestos  Paints 284,  285,  401 

Ash,  3,  30,  38,  120,  121,  122,  125, 
126,  275 

American 121 

Black 120,122,124,138 

Blue 123,  125,248 

Brown 122,124 

Cane 121 

Green 120,  125,248 

Hoop 124 

(Mineral) 17,  236,  281 

Mountain 126 

Oregon 126,248 

Prickly 126 

Pumpkin 248 

Red 122 

River 122 

Second  Growth 120 

Stinking 138 

Sugar 138 

Swamp 124,125 

Water 124,125,138 

White 120,  121, 125,  248,  273 

Yellow 126 

Aspen 169 

Large  American 172 

Largetooth 172,  248 

Quaking 172 

Associated  Compounds 26,  235 


PAGE 

Attalea  excelsa 426 

Attempts  to  Prevent  Wood  from 

Burning 282 

Automatic  Sprinklers,  289,  295,  297, 

298 
Avenarius   Carbolineum,    352,    388, 

389 


B 


Bacteria 13,  42,  268,  269 

Balluck 218 

Balm 174 

Balm  of  Gilead 73,  169,  174 

Balsa 214,246 

Balsam,   68,   73,   76,   169,   174,  275 

Canada 72,  73 

He 66 

Poplar 169,  174 

White 76 

Balsam-tree 76 

Bamboo,  4,  7,  165,  224,  225,  230,  232 

Bambusa 230,  231 

vulgaris 232 

Bands,  Rings  or  Layers,  Annual,  5,  6, 

10,  11,29,30,34,35,36,102 

Banded  Trunks  and  Woods,  5, 6,  9, 29, 

30,  34,  43,  44,  102,  169,  224 

Barium  Sulphate  (Pigment)  382,  383 

Bark 30,38,39,176,224 

Fungous  Diseases  of 272 

Green 38 

Inner  or  Fibrous 38 

Barnacles 314 

Bass 170 

Basswood.    169,  170,  176,  248,  275 

Common 176 

White 176 

Yellow 176 

Bast 38,  176 

Fibers 38,  176 

Hard 38 

Soft 38 

Bastard  Cut 40 

Bay,  Rose 195 

Bay-tree 196 

California 196 

Bayonet,  Spanish 228 

Bay  wood 208 


INDEX 


449 


PAGE 

Bead  Tree 214 

Beantree 181 

Bebeeru 201 

Bee,  Carpenter 323 

Beech,  19,  30,  152,  153,  248,  275,  375 

Blue 154,248 

European 152 

North  American 152 

Red 153 

Ridge 153 

Water 154,157 

White 153 

Beetles 56,  64,  318,  319,  320 

Attacks  by 318,319 

Colorado  Potato 318 

Beetree 170,176 

Benzine 381 

Benzol 381 

Bethell  Process  (Wood  Preser- 
vation)   %  .  363,  370,  371 

Betula 159 

alba 159 

lenta 159,164,202 

lutea 159,  163 

nigra 162 

papyrifera 159,  160,  161 

populifolia 160 

Biberine 200 

Bibiru 201 

Big-bud 147 

Bigtree 77,  101 

Birch,   43,   155,   159,  162,  248,  275, 
375 

Black 162,164 

Blue 162 

Canoe 161 

Cherry 164 

European 159 

Gray 160,  163 

Large  White 161 

Mahogany 164 

Oldfield 160 

Paper 159,  160,  161 

Poplar-leaved 160 

Poverty 160 

Red 162 

River 162,  164 

Silver 161,163 

Small  White..  .    160 


PAGE 

Birch,  Swamp 163 

Sweet 159,164,202 

Water 162 

White 160,161 

Yellow 159,163 

Bismarck  Brown,  Pigment 388 

Bitternut 146 

Black  Carpenter  Ant 323 

Blackjack 248 

Black  Scale 214 

Blackwood 215 

Bled  Woods 46,  47 

Blisted 188 

Blister  Rust 48,  50 

Bloodwood 215 

Blowdown  (see  Windfall} . .   65,  121 
Bluing  in  Wood. ...   42,  56,  251,  268 

Boards 40 

Bodark 204 

Bodock 204 

Boiling  Process  (Wood  Preser- 
vation)     372 

Boisd'Arc 202,204 

Bois  puant 157,  180 

Boleau 161 

Bookworms 320 

Bordered  Pits 18,  20 

Borers,  Stone 314 

Wood  (see  Marine  and  Land 

Woodborers) . 

Boring  Gribble,  310,  311,  312,  313 
Bot  in  Wood  (see  Decay] ...   42,  268 
Botanical  and  Common  Names .       2 
Boucherie  Process  (Wood  Pres- 
ervation)      372,  373 

Bow-wood 204 

Box 62,  191,216 

Dogwood  False 193 

Boxelder 34,133,138 

Boxwood 191,  193,  197 

American 191 

New  England 193 

Branches,  System  of 8,  9 

Brashwood. 42,  267 

Broadleaf  Trees  and  Woods,  4,  5,  6, 
29,  43,  44, 102, 103, 169,  333 
Brown,  Bismarck  (Pigment) . .  .   388 
Brush  Method  (Wood  Preserva- 
tion) . .  354 


450 


INDEX 


PAGE 

Buckeye 183,  185 

Big 185 

California 185 

Fetid 184 

Large 185 

Ohio 184 

Stinking 184 

Sweet 185 

Yellow 185,248 

Bullnut 147 

Burl 124,  139 

Burnett  Process  (Wood  Preser- 
vation)    368,  369,  371 

Burning  Woods 281,  236 

Burr  (see  Burl). 

Butadiene 435 

Butterflies  and  Moths 320 

Summary 321 

Butternut,  139,  140,  141,  143,  210, 
248 

Buttonball 156,  157,  158 

Buttonball-tree 157,  158 

Button  wood -.  .  .    157,  158 

Buxus 191 

sempervirens 191 


Cabbage  Tree 227 

Cajeput 196 

Calamus  rudentum 232 

Calathaea 426 

Calcium  Carbonate  in  Wood.  .      22 

Calcium  in  Wood 22 

Calcium  Oxalate  in  Wood 22 

Calico  Bush 195 

Callitris  quadrivalvis 387   i 

Cambium,  10,  11,  22,  34,  39,  224,  228  j 

Cork 39 

Layer 10,  11 

Camphor  Tree 198 

Camponotus    herculeanus   penn- 

sylvanicus 323 

Canada  Balsam 72,  73 

Canal,  Resin 23,  25,  26,  28 

Canals,  Primary 26 

Secondary 26 

Canker  in  Wood 42 

Canoewood..  .    171 


PAGE 

Caoutchouc    (see    Indiarubber}, 
423,  432 

Carbolic  Acid 342 

Carbolineum 352,  388,  389 

Avenarius 352,  388,  389 

Carbon     9,  234,  236,  281,  288 

Dioxide 9,  288 

in  Wood 9,  234,236,  288 

Pigment 384 

Tetrachloride 288 

Card    Process    (Wood    Preser- 
vation)     371 

Car  Painting 400 

Pullman  Company  Specifica- 
tion    400 

Care  of  Structures 298,  299 

Carpenter  Ant 32% 

Bee 323 

Worm 321 

Carpinus 154 

caroliniana 154 

Carya 145,146,147,  148 

alba 145,246 

olivceformis 148 

porcina 146 

tomentosa 147 

Casein 389 

Cassia  Bark 198 

Castanea 149,273 

dentata 108,  150,  151 

pumila 149,  151 

vesca  var.  americana 150 

vulgaris 149 

vulgaris  var.  americana 150 

Castanopsis  chrysophylla . .  .    149,  151 

Castilla  alba 427 

elastica 213,  427 

Catalpa,  30,  179,  180,  181,  207,  246,. 
273,  275 

Common 179 

Hardy 179,  180,  181,  248 

Western 180 

Catalpa 179 

bignonioides 181 

catalpa 179,  181 

speciosa 179,  180,  181,  246 

Catawba 181 

Tree 181 

Caterpillars 320 


INDEX 


451 


PAGE 

Cattle  Glues, 

Application  of 159,  408 

Manufacture  of 404,  405 

Properties  of,  405,  406,  407,  408, 
409,  410,  411,  417,  418, 
419,  420 

Protection  of 410 

Sources  of. 404 

Testing  of 417,  418,  419,  420 

Cedar,  3,  43,  85,  87,  88,  89,  90,  92,  95, 
207,  209,  386 

Atlantic  Red 89 

Australian  Red 209 

Bastard 94,214 

California  Post 94 

California  White 94 

Canoe 86,  90 

Cuban 209 

Eastern 85 

Giant 72,90 

Giant  Red 90 

Incense 86,  87,  94,  97,  272 

Lebanon 85 

Mexican 209 

Northern  White 275 

Oil 380 

Oregon 92 

Pacific  Red 90 

Pencil 87 

Port  Orford 86,92 

Post 91,94 

Red,  85,  86,  87,  90,  94,  97,  209 

Southern 85 

Southern  Red 85 

White 275 

Spanish 86,207,209 

Swamp 91 

Toon .   209 

Western 85,88,90 

Western  Red 88,  275 

White,    85,    86,    89,    91,    92,    94, 

214 
Yellow 86,88,93 

Cedrela 206,207 

australis 209 

odorata 207,  209 

Blanco 209 

toona  Roxburgh 209 

Cedrus . .  85 


PAGE 

Cells,  Companion 38 

Epithelium 25,  26 

Parenchyma 38,  39 

Pith-ray 19 

Wood  (see  Wood  Elements). 
Cell  Structures  (see  Wood  Ele- 
ments). 

Cellular  Structure  of  Wood,  17,  32 
Cellulose. .   9,  17,  234,  235,  270,  281 

Celluloid 434 

Celtis  occidentalis 152 

Cendre 87 

Census       Experiments       upon 

Woods 33,257,261 

Central  Office  System 299 

Ceraostomella  pilifera  (fungus) . .   272 

Cercocarpus  ledifolius 207 

parvifolius 207 

parvifolius  betuloides 207 

Chamcecyparis 85,  95 

lawsoniana 86,  92 

nootkatensis 93 

nutkcensis 93 

nutkatensis 86 

thyoides 86,  91 

Charring  (Wood  Preservation)  373, 

401 

Checks  in  Wood  (see  Defects  in 
Wood). 

Chelura 313,314 

Excavations 313 

Field  of  Attack 314 

Method  of  Attack 313 

Physiology  of 313 

Size  of  Borings 314 

Chelura  terebrans 313 

Chemical, 

Composition  of  India-rubber,  431, 

432,  433,  434 

Composition  of  Wood,  9,  13,  26, 
37,  38,  39,  233,  234,  235, 
237,  281 

Compounds    Applied    within 
Woods  (See  Preserva- 
tion of  Wood). 
Elements  in  Wood,  13,  26,  234,  281 

Fire  Extinguishers 289,  290 

Chemicals,  Processes  to  Introduce 

within  Woods  335, 353-375 


452 


INDEX 


PAGE 

Chene  etoile 109 

Vert 116 

Cherry 30,159,202 

Black 205,248 

Choke 205 

Red 248 

Rum 205 

Whiskey 205 

Wild 202,205 

Wild  Black 202,205 

Chestnut,  30,  108,  149,  150,  151,  273, 
275 

Blight 149,  150,  2Y2,  273 

Evergreen 149 

North  American 149 

China 214 

China-berry 214 

China  Wood  Oil 214,  380 

China  Wood  Oil  Tree 214,  380 

Chinquapin 149,  151 

California 149 

Common 149 

Goldenleaf 149 

Western 149 

Chlorophyll 9,  13,  38,  235,  268 

Chloroxylon 215 

swietenia 215 

Chrome  green  Pigment 382 

yellow  Pigment 382 

Cigar  Tree 180,  181 

Indian 181 

Cinnamomum 198 

camphora 198 

cassia 198 

zeylanicum 198 

Cinnamon  Tree 198 

Citronella 380 

Citrus  aurantium 127 

trifoliata 127 

Cladrastis  tinctoria 126 

Clam,  Long 301 

Razor 301 

Softshelled 301 

Classifications,  Fundamental,  1,  4,  5, 
6 

Coach  Painting 400 

Coatings  for  Woods .   377,  400 

Coefficient  of  Elasticity,  33,  238,  239, 
261 


PAGE 

Coefficient  of  Rupture.  .33,  239,  261 

Coffee 152 

Coffeebean 152 

Coffeebean-tree .    152 

Coffeenut 152 

Coleoptera 319 

Colophony. 388 

Color  Defined 251 

Color  of  Wood 251 

Coloring  Matter  in  Wood ...   17,  251 
Common  and  Botanical  Names .       2 

Companion  Cells 38 

Comparison,  Woods  with  Stones 

and  Metals  xvii,  1,  2,  255 
Compounds     Associated     with 

Woods 26 

Associated    with    Wood-ele- 
ments     17,26 

Inorganic 26,  236 

Organic 26,  234 

Conductivity  (Defined) 248 

of  Wood 237,248 

Cone-bearers  (see  Conifers). 

Cones  (see  Conifers) 44 

Confederate  Pintree 167 

Conflagrations    Influenced    by 

Wood 277,280,294 

Coniferae  (see  Conifers). 
Coniferous  Trees  (see  Conifers) 

Woods  (see  Conifers). 
Conifers,  4,  5,  6,  20,  30,  34,  43,  44, 
102 

Conservation xvii 

Consumption  of  Wood 1 

Convolvulus  scoparius 214 

Copal 386 

Manila 386 

Sierra  Leone 386 

South  American 386 

Zanzibar 386 

Copper  Sulphate,   Effect  upon 

Wood .   337,338,  374 

Cork 246 

Cork  Cambium 39 

Corkwood,  Missouri 246 

Corky  Layer 39 

Cornel 193 

Flowering 193 

Cornus..  .    191 


INDEX 


453 


PAGE 

Cornus,  florida 191,  193 

Cortex 38,39,224 

Cossus  ligniperda 321 

Cotonier 157 

Cotton  Tree 173 

Cottonwood,  30,  169,  173,  174,  275, 
375 

Balm 174 

Balsam 174 

Big 173 

Black 175,248 

Broadleaved 173 

Yellow 173 

Cotton  Wool 234 

Cotyledon 4,  9 

Cracks  in  Wood,  (see  Defects  in 

Wood) 40 

Creoaire  Process  (Wood  Preser- 
vation)     374 

Creo-resinate     Process     (Wood 

Preservation 372 

Creosote,  281,  317,  318,  322,  337,  339, 
340,  341,  342,  343,  344,  345, 
346,  347,  348,  349,  350,  351, 
375,  376 

Analysis  of 344,  348,  349,  350 

Constituents  of 341,  342 

Distribution  of 351 

Effects  upon  Wood 340,  341 

Mixed 343 

Required  Quantities  of 351 

Sources  of • 341 

Specifications,  344,  345,  346,  347, 
348,  349,  350 

Cresylic  Acid 342 

Cross-surfaces  of  Wood 39 

Croton  lacciferus 387 

Crude  Sap 11,235 

Cryptogams 269 

Cucumber 175 

Cucumber-tree 169,  171,  175 

Cupressus 95 

macrocarpa 95 

Cup  Shakes  in  Wood  (see  De- 
fects in  Wood) 41 

Cut,  Bastard 40 

Quartered 39,  40,  334 

Tangential 24,40 

Cycadaceoe 4 


PAGE 

Cylinders,  Use  of 360 

Cynoxylonfloridum 193 

Cypress,  3,  85,  86,  87,  94,  95,  97,  246, 
272,  275 

Alaska 93 

Alaska  Ground 93 

American ... 96 

Bald. 96,97 

Black 96,  97 

Common 95 

Deciduous 97 

Evergreen 95 

Lawson 92 

Monterey 95 

Nootka 93 

Nootka  Sound 93 

Red 96,97 

Sitka 93 

Southern 97 

Swamp 86,  97 

White.. 96,97 

Yellow 93,96 

Cyst 25 

D 

Doedalea  vorax  (fungus) .   96,  97,  272 

Dagger,  Spanish 228 

Dalbergia  nigra 214 

sissoo 213 

Dammara 62,  387 

australis 63,  221,  387 

orientalis 387 

Date,  Plum 203 

Wild 226 

Deal 59 

White 64 

Decay  in  Wood,  42,  96,  265,  266,  268, 
269,    270,    271,    272,    273, 
274,  275,  276 
Deciduous  Trees  and  Woods,  4,  6, 

43,  103 
Defects  in  Woods .  .   40,  41,  42,    333 

Deformation  in  Woods 237 

Dendrocalamus 231 

Dendroctonus  piceaperda 64 

ponderosa 56 

Density  of  Woods,  237,  244,  246,  247 

Density  Rule 46,  260 

Density  Test 46,  245,  260 


454 


INDEX 


PAGE 

Deposit,  Annual,    (see   Annual 
Ring  Bands  or  Layers). 

Springwood 30,  31,  35,  36 

Summer-wood. . .   30,  31,  35,  36 
Destruction  Woods,  by  Age,  266,  267 

by  Ants 321,  323,  324 

by  Bees 323 

by  Beetles 319,  320 

by  Chelura 313 

by     Decay    (see      Decay    in 
Woods'). 

by  Exposure 267 

by   Fire,  277,  280,  281,  282,   283, 

284,  285,  286 

by  Limnoria.  .  .  310,  311,  312,  313 
b  y    Miscellaneous    Wood- 

borers     314 

by  Moths  and  Butterflies,  320,  321 

by  Shipworms,  225,  300,  307,  308, 

309,  310,  315,  316,  317,  318 

by  Termites 321,  322,  323 

by  Use 267 

Destructive  Temperatures 293 

Diaporthe  parasitica   (fungus),    149, 

150,  272,  273 
Dicotyledons,  4,  5,  6,  30,  34,  43,  102, 

169 
Dicotyledonous       Trees       and 

Woods  (see  Dicotyledons') . 

Diffuse-porous  Woods 30,  31 

Diospyros 202 

chloroxylon 202 

ebenaster 202 

ebenum 202,  246 

mespiliformis 202 

virginiana 202,203 

Dipping  Method  (Wood  Preser- 
vation)     354 

Direct  Physiological  Properties .  233 
Disease,  Bark. . . .   149,  150,  272,  273 

Black  Scale 214 

Blister  Rust 48,50 

Chestnut  Bark,  149,  150,  272,  273 

Foliage... 272 

Roots 272 

Trunks  and  Trees.  .   268,  271,  272 
Woods  (see  Decay  in  Woods). 

Distortion  of  Wood 264 

Distribution  of  Species 16 


PAGE 

Dogwood 191,  193 

Flowering 191,  193,  248 

Poison : 193 

Doors,  Fireproof,  284,  285,  295,  296, 
402 

Dote  in  Wood 42,  268 

Douglas  Fir 25,  246 

Douglas  Tree 71 

Dragon-tree 224 

Driers 379,380 

Japan 380 

Dry  Rot  in  Wood 42,  268,  274 

Duct 21 

Resin     (Wood  Element),    23,  25, 

26,  28 
Durability  of  Wood,  266,  274,  275, 

276 
Duramen 37 

E 

Ebenaceoe 202 

Ebonite 434 

Ebony 202,246 

Green 202 

Madagascar 202 

Mexican 202 

Edge-grained  Woods 40 

Edging 40 

Elaborated  Sap 11,  37,  235 

Elasticity  (Denned) 240 

Modulus  of 33,  238,  239,  261 

of  Wood 18,33,237,240 

Electrical       Conductivity       of 

Wood 248 

Elements,  Chemical,  in  Wood,  13, 17, 

26,  234,  281 

Wood  (Cell-Structures),  17,  18,  19, 
20,  21,  22,  23,  24,  25,  26,  27, 
28,29,30,31,32,34,38,39, 
44,  102,  224,  225,  237,  247, 
248,  249,  252 
Elm,  3,  43,  92,  102,  128,  129,  132,  248 

American 129 

Cliff 130 

Cork 130,132 

Corky 132 

False 152 

Hickory 130 

Moose..  .    131 


INDEX 


455 


PAGE 

Elm,  Mountain 132 

Red 131,132 

Redwooded 131 

Rock 130,  131 

Slippery 129 

Small-leaved 132 

Wahoo 132 

Water 129 

White 129 

Wing 132 

Winged 132 

Witch 132 

Empty   Cell    Processes  (Wood 

Preservation), 351,  362,  363, 
369 

Enamelled  Paints 378,  398 

Encena 117 

Endogen 6,  7,  224 

Endothia  gyrosa  (fungus),  149,  150, 

272,  273 
Endothia  gyrosa  var.  parasitica 

(fungus),  149,  150,  272,  273 

Entandrophragma  candollei 206 

Enzyme 270 

Epidermis 39 

Epithelium  Cells 25 

Eppinger  &  Russell  Specification,  364 

Erosion  (Soil) 14,  15 

Eucalypt,  Giant 223 

Eucalyptus,  26,  216,  217,  218,  219, 
220,  221,  222,  223,  248 

Blue  Gum 248 

Eucalyptus 216 

amygdalina 216,  223 

colossea 221 

corynocalyx 223 

diversicolor 216,  221 

globulus 216,217,218 

gomphocephala 216,  222 

leucoxylon 246 

macrorrhyncha 223 

marginata 216,  220 

resinifera 223 

rostrata 216,  219 

viminalis 223 

Euphorbiacece 214 

Evergreen  Trees  and  Woods  (see 

also   Coniferous  Trees  and 
Woods)    ...  4  6,  43,  44,  81 


PAGE 

Examinations,  Microscopical,  30,  31, 
247 

Exogen 5,  6 

Experiments  (see  Tests). 

Physical,  Woods,  33,  243,  251,  252, 

255,  256,  257,  258,  259,  261 

Railroad  Spikes 242 

Exposure,  Woods  Destroyed  by,  266, 
267,  268,  273,  274,  275,  276 

External    Preservative    Treat- 
ment of  Woods,  266,  273, 
274,  282,  284,  285,  286,  315, 
316,  317,  324,  334,  377  to 
401,  410 


Fagus 152 

americana 19,  152,  153 

atropunicea 153 

ferruginea 153 

grandifolia 153 

sylvatica 152 

Families  (Defined) 3 

Fastenings  for  Woods 237,  242 

Feather-cone 77 

Ferns 269 

Ferrell  Process    (Wood   Preser- 
vation)     374 

Fever  Tree 218 

Fibers,  Wood,  18,  19,  20,  22,  25,  30, 

102,  247 
Wood-parenchyma.  ...    19,  22,  24 

Fibrous  Bark 38 

Ficus  elastica 213,  427 

sycomorus 156 

Fig  Tree 156 

Figures  Relating    to     Physical 

Properties    of   Woods,    33, 
257,  258,  259 

Fillers,  Wood 384,  385,  396,  397 

Fir 3,43,64,65,70,72 

Balm  of  Gilead 73 

Balsam 72,73,76 

California  Red 75 

California  White 76 

Colorado  White 76 

Common  Balsam 73 

Concolor  White 76 

Dantzic . .  59 


456 


INDEX 


PAGE 

Fir,  Douglas 70,  71,  246,  275 

Golden 75 

Great  Silver 74 

Lowland 74 

Magnificent 75 

Memel 59 

Noble 72,77 

Noble  Red 77 

Noble  Silver 77 

Northern 59 

Oregon  White 74 

Prince  Albert's 79 

Red 70,71,72,75,77,78 

Red-bark 75 

Rigi 59 

Scots 59 

Scottish 59 

Silver 72,74,76 

Stettin 59 

Swedish 59 

Tree 73 

Western  Hemlock 79 

Western  White 74 

White 64,74,76 

Yellow 70,71,74 

Fire,  Apparatus,  280,  287,  288,  289, 
290,  291,  292 

Burning  Woods 236,  281 

Coatings 284,  285,  286 

Application 284,  286 

Extinguishers,  Chemical.  289,  290 

Sprinklers 297,  298 

Extinguishing  Materials 288 

Losses 278,279,280 

Indirect 278 

Pails 290,291,292 

Protection 280,282,284,292 

Retardants 282,  283 

Risks 15 

Signals 298 

To  Extinguish 280,  287 

Underwriters'  Specifications-  297 

Woods  Destroyed  by 277 

Fireproof  Buildings 294 

Doors 284,  285,  295,  296,  402 

Materials 294,  295 

Paints 284,285,402 

Shutters 285,295,296 

Windows..  .   296 


PAGE 

Fireproof ed  Woods .  .  .   282,  286,  402 
Fires  in  Buildings,  Prevention .  .    294 

First-growth  Woods 120 

Fish  Glues,  Application  of 414 

Manufacture  of 411,  412 

Properties  of 413 

Sources  of 411 

Fistulse 21 

Flax 38,  379 

Flax  Fiber  (see  Cellulose) 234 

Flea  (Wood  flea) 310 

Floods 14 

Foliage,  Fungous  Diseases  of ...   272 
Forest  Service,  National,  Speci- 
fication for  Creosote . .   348 

Forest  Top-soil 13 

Forests 13,  14,  15 

Influence  on  Erosion 14,  15 

on  Rainfall 14,  15 

on  Streamflow 14,  15 

Value  of 13 

Forestry 15 

Formalin 408,  410 

Forms  of  Trees 12,  13 

Fossil  Resin 62,  386,  387 

Fraxinus 120 

americana 120,  121 

lanceolata 120,  125 

nigra 120,  124 

oregona 126 

pennsylvanica 122,  125 

pennsylvanica  var.  lanceolata. .    125 

pubescens 122 

quadrangulata 123 

sambucifolia 124 

viridis 125 

Fresh  Water  Wood-borers 314 

Frost  Shakes  in  Wood 41,  333 

Full  Cell  Processes,  Wood  Pres- 
ervation, 351,  361,  362,  363, 
368,  369,  371 

Fundamental  Classifications,  1, 4, 5, 6 
Fungi,  13,  42,  64,  96,  149,  150,  262, 
,  263,  268,  269 

Bread 269 

Fungous  Diseases 267,  273 

Bark 149,  150,  272,  273 

Contagion 276 

Foliage.... 272 


INDEX 


457 


PAGE 

Fungous  Roots 272 

Structural  Woods  273,  274,  275, 

276 

Trees  and  Woods.  .  .   268,  271,  273 
Trees..  .   271 


Gallic  Acid 104,119 

Gelatine 403,  404,  410,  411 

Genereso 210 

Genus 3,  32 

Gleditsia 165 

triacanthos 165,  167 

Glues,  159,  206,  208,  337,  389,  403, 
404,  405,  406,  407,  408,  409, 
410,411,  412,413,414,415, 
416,  417,  418,  419,  420 

Action  of 410 

Appearance  of 408,  413 

Application  of .  .159,  337,  408,  414 

Cattle,   403,   404,   405,   406,   407, 

408,  413,  417,  418,  419,  420 

Failure  of 407 

Fish.    159,  337,  403,  411,  412,  413, 

414,  420 
Liquid  (see  Fish  Glues) . 

Specifications 408,  409,  417 

Tests 417,418,419,420 

Uses  of 414 

Woods,  Prepared  for 408,  414 

Gnetacece 4 

Gopher  Plum 189 

Wood 95,126 

Grain  of  Wood 26,  27,  28,  39 

Graphite 384,  434 

Greenheart 200,  201,  246,  275 

Black 201 

Gray 201 

Yellow... 201 

Gribble 310,  311,  312,  313 

Boring 310,  311,  312,  313 

Growth,  Length 9,  12 

Thickness 9 

Tree 9,12,32 

Guadua 231 

Guajac 191 

Guajacum 191,  194 

arboreum 194 

officinale 191,  194 


PAGE 

Guajacum,  sanctum.  .  .  191,  194,  246 
Guayule  (Indiarubber),  213,  426,  427 
Gum  (Excretions),  25,  37,  62,  165, 

234,235,385 
Gum  (Trees),  186,  188,  190,  216,  218, 

219,  220,  221,  222,  223 
Gum,  Black.. . .    19,  76,  187,  190,  248 

Blue 216,  217,  218,  248 

California  Red 186 

Cotton 21,  189 

Mahogany 220 

Manna 223 

Red,  102,  141,  186,  187,  188,  216, 
219,  223,  248 

Sour 187,  189,  190 

Star-leaved 188 

Sugar 223 

Sweet 31,  186,  188 

Tree 186,  188,216 

Tree,  Yellow 190 

Tupelo 186,  189,  190 

Water 186,248 

White 221,222 

Gumbo  file 199 

Gymnocladus  dioicus 152 

Gymnosperms 4 

H 

Hackberry 152 

Hackmatack 83,84 

Hard  Bast 38 

Hardhack 155 

Hardness  (Defined) 241 

Hardness  of  Wood,  18,  237,  241,  245 

Hardshell 146 

Hardwood  Mfrs.'  Asso.  Specif.     42 

Trees  and  Woods 4,  6,  43,  102 

Hardwoods 4,  6,  43,  102 

Hasselmann      Process      (Wood 

Preservation) 374 

Hayford  Process  (Wood  Preser- 
vation)     364 

;  Hazel 186,  188 

!   Heart  Shakes  in  Wood  (see  De- 
fects in  Wood) 41 

Heartwood  25,   34,  37,  38,  47,  246, 

247,  262,  351 

Heat,  Conductivity  of  Wood .  .   248 
Effect  upon  Wood,  266,  329,  361 


458 


INDEX 


PAGE 

Hedge 204 

Hedge-plant 204 

Hemlock,  3,  43,  44,  65,  78,  79,  80, 
275,  375 

Alpine 78 

Bastard 70 

Black 79 

Carolina 80 

Eastern 78 

Southern 80 

Spruce 78,  80 

True  Black 78 

Western 78,79 

Hevea  brasiliensis 213,  427 

Hevea  rubber,    213,  422,  424,  425, 
427 

Heyderia  decurrens 94 

Hickory,  3,  4,  30,  43,  92,  140,  144, 
145,  147,  246 

Bitternut 248 

Black 146,  147 

Broom 146 

Brown 146 

Common 147 

Hard  Bark 147 

Mocker  Nut . . . 147 

Nut 147 

Nutmeg 248 

Pecan 148 

Pignut 146 

Red 146,147 

Scalybark 145 

Second-growth 120,  144 

Shagbark 145,248 

Shellbark 145,248 

Switchbud 146 

Upland.. 145 

White 92,  145,  146,  147 

Whiteheart 147 

Hicoria 144 

alba 147 

glabra 146 

ovata 145 

pecan 148 

HogNut 147 

Holly 30,  191,  192,  248 

American 192 

European 191 

White..  .   192 


PAGE 

Honey 167 

Pod 168 

Shucks 167 

Horizontal  Wood-structure ....      26 

Hornbeam 154,  155 

Hop 155 

Horse  Chestnut 183 

American 183 

California 185 

Humus 13,  14 

Husk 38 

Hygroscopicity 251 


Identification     of     Trees     and 

Woods 17,27,  28,  29, 

30,  31,  32,  36 

Idioblasts 22 

Ilex 191 

aquifolium 191 

opaca 191,  192 

Impact  Testing  Machine 245 

Importance  of  Wood 1 

Indian  Bean 180,  181 

Indian  Cigar  Tree 811 

Indiarubber,  213,  421,  422,  423,  424, 
425,  426,  427,  428,  429,  430, 

431,  432,  433,  434,  435 
Chemical    Composition    of,    431, 

432,  433,  434 
Classification  Due  to  Form . .   429 

Crude 427,428,433 

Fresh 427,428 

Grades  of 426 

Guayule 213,426,427 

Latex,  421,  422,  423,  424,  425,  426 

Para 213,  423,424,427 

Physical  Properties  of 431 

Plantation 428 

Preparation  of 429,  430,  431 

Properties  of . . .   431,  432,  433,  434 

Pure 423,432 

Purification  of 429,  430,  431 

Reclaimed 427,428 

Refined 427,428 

Shrub 213,427 

Sources  of 213,426,427 

Synthetic 435 


INDEX 


459 


PAGE 

Indiarubber,  Uses  of 434 

Vulcanized 430,  431,  433,  434 

Wild 428 

Indiarubber  Tree 213,  427 

Assam 213,427 

Central  American 427 

Hevea  ....   213,  422,  424,  425,  427 

Indiarubber  Vine 427 

Ink,  Printer's 380 

Inlaid  Work 191,  192,  416,  417 

Inorganic  Compounds  in  Wood,  26, 

236 

Inorganic    and    Organic   Mate- 
rials,     Comparison,     xvii, 
xviii,    233,    234,  236,  237, 
255,  281 

Insects, 318 

Associated  with  Fungi 271 

Hosts  ,of  Micro-organisms.  .  .  271 
Woodborers,   318,   319,   320,  321, 

322,  323,  324,  325 
Woods  Protected  from .  '.  324,  325 

Inside  Growth 6,  7,  9,  224 

Internal      Preservative     treat- 
ment of  Woods,  266,   282, 
283,  284,  317,  322,  334,  335 
to  376 

Introduction xvii 

Ironbark 216,  223,  246 

Iron  Oxide  Pigments 383 

Ironwood 154,  155,  168,  194 

Isinglass 411 

Isoprene 435 

Isoptera 321 


Japan 380,  381 

Jarrah 216,220 

Jenicero 210 

Joints,  Wood  and  Glue,  410,  411,  414 

Joshua-tree 228,  229 

Juglans 139 

australis 141 

calif  arnica 140 

cinerea 139,  140,  141,  143 

insularis 141 

nigra 19,  21,  22,  23,  139,  142 

regia 139,  141,209 

rupestris 140 


PAGE 

Juniper 83,  85,  87,  88,  91,  94 

Bush 87 

California 88 

Red 87 

Western 88 

Juniperus 85 

barbadensis 85,  86 

calif ornica 88 

occidentalis 88 

scopulorum 85,  86 

virginiana 85,  86,  87 


K 


Kalmia  latifolia 195 

Kalsomine 389 

Karri 216,220,221 

Kauri  Pine 62,  63,  387 

Kauri  (Resin)  .  62,  63,  385,  387,  388 

(Tree) 62,  63,  387 

Khaya 206 

grandifolia •. 206 

senegalensis 206 

Kiln    Drying    of  Wood   (Wood 

Preservation) 327,  328 

329,  330,  331,  332,  333,  334 

Kilns,  Forms  of 330,  331,  332 

Knots   (see  Defects),  41,  42,  43,  45, 
333 

Encased 42 

Large 43 

Loose 42 

Pin 43 

Pith 42 

Rotten 43 

Round 43 

Sound 42 

Spike 43 

Standard 43 

Kyan     Method     (Wood      Pre- 
servation)    355 


Lamella,    Middle    (Wood    Ele- 
ments)        18 

Land  Life,  W'oods  Destroyed  by, 

266,  309,  310,  313,  318,  320, 
322 


460 


INDEX 


PAGE 

Land  and  Marine  Woodborers,  225, 
300,  301,  302,  303,  304,  305, 
306,307,308,309,310,311, 
312,  313,  314,  315,  316,  317, 
318,  320,  321,  322,  323,  324, 
325 

Landolphia  dawei 427 

heudelotii 427 

kirkii 427 

owariensis 427 

thollonii 427 

Larch 70,  77,  81,  82,  83,  84,  96 

American 83 

Black 83 

Eastern 81 

European 81,82 

Great  Western 84 

Red 83 

Red  American 84 

Western 81,  84 

Larix 81 

americana 81,  83,  84 

europcea 81,  82 

laricina 83 

occidentalis 81,  84 

Latex  (Indiarubber),  421,  422,  423, 
424,  425,  426 

Laurel 195,  196,  197 

Big 195 

California 195,  196 

Great 193,  195 

Madrona 195,197 

Mountain 195,  196 

Laurelwood 197 

Layers,  Cambium  (see  also  Cam- 
bium}   10,  11 

Bands,  or  Rings,  Annual,  5,  6,  10, 
11,  29,  30,  34,  35,  36,  39, 
46,  102,  260 

Corky 39 

Concentric 5 

Lead,  Oxide,  Pigment 380 

Red,  Pigment 383 

White,  Pigment 378,  382 

Leaf -system  of  Tree 9 

Leaves 9 

Leguminosce 165 

Leitneria  floridana 246 

Length-growth  of  Trees 9,  12 


PAGE 

Lepas  antifera 314 

Lepidoptera  (Insects) 320 

Lepisima  saccharina  (Beetle) .  .  .   320 

Leverwood 155 

Libocedrus 85 

decurrens 86,  94 

Lichens 269 

Life,  Animal,  Woods  Destroyed 

by 266,300 

Light,  Influence  of 12,  13 

Lignin 11,  17,  234,  235,  270,  281 

Lignumvitae,   26,  191,  194,  201,  246, 
275 

Lime 170 

Ogeechee 189 

Lime  Tree,  Black 176 

Smooth-leaved 176 

Limetree 170,  176,  189 

Wild 189 

Limnoria. .  .   310,  311,  312,  313,  340 
Effects  of  Temperature  and 

Water 311 

Excavations 311 

Field  of  Attack 313 

Form  and  Physiology  of 310 

Methods  of  Attack 311 

Rapidity  of  Attack 312 

Size  of  Borings 311 

Woods  Subject  to  Attack. ...   313 

Limnoria  lignorum 310 

Lin,  Black 175 

Lind 170 

White 176 

Linden 170,176 

American 176 

Linn 176 

Linoxyn 379,383 

Linseed  Oil 379,  380,  383,  389 

Liquidambar 186,  188 

Liquidambar 186 

styraciflua 141,  186,  188 

Liriodendron 169 

tulipifera 169,  171,  175 

Litharge 383,434 

Live  Oak 105,  116,  118,  246 

Locality  of  Species 16 

Locust 165,166,167,246 

Black,  30,  165,  166,  167,  248,  275, 
375 


INDEX 


461 


PAGE 

Locust,  Green 166 

Honey. .  .  .    165,  166,  167,  168,  248 

Honey  Shucks 167 

Pea-flower 166 

Post 166 

Red 166 

Sweet. 167 

Thorn 167 

Thorny 167 

White 166 

Yellow 166 

London,     Brighton     &     South 
•     Coast    Railway    Spec. 

(Creosote) 364 

Long  Clam 301 

Longshucks 55 

Lowry  Process    (Wood   Preser- 
vation)    370,  371   j 

Lumber  (defined) 17 

Rolled 41 

Lumen 18,  19 

Lysiloma  sabicu 213 


M 


Madura  aurantiaca 204 

Madeira 208 

Madrona.... 195,  197 

Mexican 197 

Madrone 197 

Madrone-tree 197 

Madrove 197 

Magnolia 169,  175,  195,  248 

Mountain 175 

Magnolia 169,  195 

acuminata 169,  175 

fcetida 195 

Mahogany,  152,  159,  202,  206,  208, 
216,  220,  246,  396,  416 

African 206,212   | 

American 163 

Birchleaf 207 

Central  American 206 

East  Indian 206 

Frontera 206,  208 

Honduras 206,  208  ! 

Mexican 208 

Mountain 164,  207 


PAGE 

Mahogany,  Philippine 206 

Primavera 207 

Red 206,223 

Spanish 206,208 

Valley 207 

White 143,207,210 

Maintenance  of  Structures 298 

Mammoth  Tree 101 

Manzanita 197 

Maple,  3,  4,  30,  43,  102,  133,  137, 
156,  246,  248,  375 

Ash-leaved 138 

Birdseye 40,  133 

Black 134 

Blister 133 

Broad-leaved 137 

Curly 40,  133 

Cut-leaved 138 

European 133 

Hard 40,133,134 

Negundo 138 

Oregon 137 

Red 136 

Red  River 138 

River.. 135 

Rock 134 

Silver 129,  135 

Soft 133,135,136,272 

Sugar 133,134 

Swamp 135,  136 

Three-leaved 138 

Water 135,  136 

White 135,  136,  137 

Marine  and  Land  Wood-borers,  225, 
300,  301,  302,  303,  304,  305, 
306,  307,  308,  309,  310,  311, 
312,  313,  314,  315,  316,  317, 
318,  320,  321,  322,  323,  324, 
325,  340 
Marine  Life,  Woods  Destroyed 

by,  225,  266,  309,  310,  315, 
322 

Woods  Protected  from,  315,  316, 
317,  318,  320,  322,  323,  324, 
325 
Marsonia  ochroleuca  (fungus) .  .   272 

Mastic 388 

Materials,       Associated      with 

Wood, 235 


462 


INDEX 


PAGE 

Materials,  Chemical    Composi- 
tion of  Wood,  9,  13,  26,  37, 
38,  39,  233,  234,  235,  237, 
281 

Fireproofing 294 

Fire  retardants 282,  283 

Inorganic,  17,  233,  234,  236,  237, 

255,  281 

Organic,  9,  11,  19,  37,  234,  235,  236 

Physical   Properties   of,   33,  '  237, 

238,  239,  240,  241,  242,  243, 

244,  245,  246,  247,  248,  249, 

250,  251,  252,  255,  256,  257, 

258,  259,  260,  261 

Physiological  Properties  of. .  .233 

Wood     Preservatives,    337,    338, 

339,  340,  341,  342,  343,  344, 

345,  346,  347,  348,  349,  350, 

351,  352 

Measurements,  Physical  Proper- 
ties ....  251,  252,  255,  256 

Medulla , 37 

Medullary  Ray 24,  40 

Meliacea 207 

Melia  azedarach 214 

Mercury  Bichloride 337,  338 

Merisier 163 

Rouge 163 

Mesquite 165,  168,  275 

Screwpod 165 

Metals xvii,  277,  295 

and   Woods,  Comparison  xvii,   2, 

255 

Metal  Coatings,  273,  286,  295,  316, 
400 

Micro-organisms,  Soil 275 

Microscopes 31 

Microscopic   Examinations,   30,   31, 
32,  247 

Microtomes 31,  32 

Middle    Lamella    (Wood    Ele- 
ment)        18 

Mildew  (see  also  Decay) 42 

In  Foliage 272 

In  Wood 42,268 

Mineral  Matter  in  Wood,  17,  236,  281 

Missouri  Corkwood 246 

Mock  Orange 204 

Mocker  Nut..  .    147,248 


PAGE 

Moduli  and  Weights  of  Woods,  33, 

238,  239,  261 

Moisture  in  Woods,  17,  26,  234,  237, 
245,  246,  252,  258,  262,  263, 
264,  265,  329 
Mollusk   (see  also  Shipworm),  225, 

330 

Monocotyledons,    4,    5,    6,    7,    224, 
230 

Morus 182 

alba 182 

celtidifolia 182 

rubra 182 

Mosses 269 

Moths  and  Butterflies 320,  321 

Goat 321 

Gypsy 320 

Mould  in  Wood 268 

Movement,  Sap 11 

Mucilage  (Defined) 62 

Mulberry 182 

Black 182 

Mexican 182 

Red 182,248,275 

Tree,  Virginia 182 

White 182 

Murier  Sauvage 182 

Mya  arenaria 301 

Myrtle-tree 196 


N 


Nails,  Teredo 316 

Worm 316 

Names,  Common  and  Botanical,  2, 47 

Naphthalene 341,  342 

National    Forest    Serv.    Exper.,  33, 

258,  259,  260,  261 

Natural  Seasoning 276,  327 

Naval  Stores 15,  47,  53,  58 

Nectandra 200 

rodioei 200,201,246 

Nectria  cinndbarina  (fungus) .  .  .    269 
Needleleaf  Trees  and  Woods,  4,  6, 

29,  36,  43,  44 

Negundo  aceroides 138 

Neowashingtonia  filamentosa.  .  .   226 

Nettle-tree 152 

Nogal 141 


INDEX 


463 


PAGE 
Nomenclature,        Trees       and 

Woods 2,47 

Non-banded        Trunks        and 

Woods 6,9,29,224 

Non-coniferous       Trees       and 

Woods 6,43,102,103 

Non-durable  Woods 275 

Non-porous  Woods 30,  31 

Non-pressure  Processes  (Wood 

Preservation) 353,  355 

Non-seedbearing  Plants 269 

Noyer 141 

Nyssa 186 

aquatica 21,  186,  189 

multiflora 190 

ogeche 189 

sylvatica 19,  187,  190 


o 


Oak,  3,  4,  5,  21,  24,  30,  43,  102,  104, 
151,  152,  333,  334 

African 212 

Basket 107 

Black 105,112,115 

BlackLive 118 

Box 109 

Box  White 109 

Brash 109 

British 119 

Bur 105,110,248 

California  Live 105,  117 

California  Post Ill 

California  White Ill 

Canyon 118 

Canyon  Live 118 

Chestnut 105,  108,  119 

Coast  Live 117 

Common 119 

Cork 246 

Cow 105,107,248 

Dantzic 119 

Durmast 119 

Dyer's 115 

English 104,  119 

Evergreen 117 

Garry 248 

Golden-cup 118 

Highland  Live 118 


PAGE 

Oak,  Indian 212 

Iron 109,118 

Live 105,116,118,246 

Maul 118 

Mossycup 110 

Mossycup  White 110 

Mountain 108 

Oregon  White Ill 

Overcup 109,  110,  248 

Overcup  White 110 

Pacific  Post 105,  111 

Pin 32,  105,  113 

Post 105,109,248 

Quarter-Sawn 24,  39,  40,  334 

Quercitron 115 

Red,  20,  32,   105,   112,   114,   119, 
150,  246,  275,  375 

Rigi 119 

Rock 108 

Rock  Chestnut 108 

Scrub v.   110 

Spanish 105,112,114 

Spotted 115 

Stave 106 

Swamp Ill,  113,375 

Swamp  Chestnut 107,  108 

Swamp  Spanish 113 

Swamp  White. 107,  248 

Tanbark 108,115 

Valley Ill,  248 

Valparaiso 118 

Water 113 

Water  Spanish 113 

Weeping. Ill 

Western  White Ill 

White,   19,  22,  28,  31,   105,   106, 
109,  111,  246,  248,  275,  375 

Yellow 105,  115 

Yellow-bark 115 

Ochroma  lagopus 214,  246 

Oil 79,80,378,381,385 

Boiled 379,  480 

Cedar 380 

China  Wood 214,  379,  380 

Citronella 380 

Elaeococca 380 

Linseed 379,  380,  383,  389 

Lithographic 380 

Non-solidifying 379,  381 


464 


INDEX 


PAGE 

Oil,  Nut 143 

Raw 379,380,392 

Rubber 379 

Sandal  Wood 380 

Solidifying 379,  380 

Tung 214,379,380 

Volatile 379,  381 

Walnut 379 

Oils,  Paints  and  Varnishes 377 

Oldfieldia 211 

africana 211,  212 

Olea  europcea 127 

Olive 127 

California 196 

Olive  Tree 189 

Wild 189 

One-berry 152 

Open  Tank  Process  (Wood  Pres- 
ervation),   355,    356,    357, 
358,  359,  360 

Orange 127 

Mock 204 

Osage 92,  202,  204,  248,  275 

Oreodaphne 196 

Oreodoxa  regia 6,  225 

Organic  and  Inorganic  Materials, 

Comparison,  xvii,  1, 233, 355 
Organic  Compounds  in  Woods,  9,  11, 

19,  37,  234,  235,  236 
Organic     Origin,     Influence     upon 
Properties  of  Woods,  233, 
234,  235,  262,  264 

Osage 204 

Apple  Tree 204 

Orange 92,  202,  204,  248,  275 

Ostrya 154 

virginiana. 154,  155 

Outside-growing  Trunks 5,  6 

Oxygen  in  Wood 234,  281 

Ozonium  omnivorum  (fungus) .  .   272 


Padus  serotina 205 

Paint,  Application  of,  389,  390,  391, 
392,  393,  394,  395,  398,  399, 
400 

Asbestos 284,401 

Casein 389 

Covering  Capacity 394 


PAGE 

Paint,  Denned 377 

Durability  of 398 

Enamel 378,  398 

Failure  of 389,  390,  391 

Fireproof 284,  285,  402 

Miscellaneous   Applications,    388, 

389 

Pigments,  378,  381,  382,  383,  384 
Preparation  of  Woods  to  Re- 
ceive     402 

Priming  for 380,  390,  393 

Removal  of 390,  391 

Sprayed 391 

Upon  New  Surfaces 390 

Upon  Old  Surfaces 390 

Water 389 

Waterglass 285,  401 

Woods  Prepared  For 402 

Painting,  Car 400 

Coach 400 

Ship... 399 

Palm 4,7,224,225 

Arizona 226 

California  Fan 226 

Date 226 

Desert , 226 

Fanleaf 225,226 

Nut 426 

Royal 6,225 

Sargent 225 

Washington 225,  226 

Palmacece 225 

Palmetto 225,227 

Cabbage 225,227 

Mexican 225,  227 

Prickly  Thatch 227 

Silktop 225,227 

Silver  Thatch 227 

Silvertop 225 

Paraffine 281,  316 

Parasites  (see  Bacteria) 269 

Parenchyma  Cells ....  24,  30,  38,  39 

Ray 30 

Paris  White,  Pigment 389 

Parthenium  argentatum 427 

Paulownia 180 

Paulownia  tomentosa 180 

Pear 127 

Tree,  Wild 190 


INDEX 


465 


PAGE 

Pecan 148 

Nut 148 

Pecan-tree 148 

Pecanier 148 

Peckiness 93,  272 

Penetrability 247 

Pepper 213 

California 213 

Longleaved 213,  214 

Pepperidge 190 

Peppermint  Tree 216,  223 

Perishable  Woods 275 

Persimmon 30,  202,  203,  248 

Black 193 

Mexican 193 

Peruvian  Mastic 213 

Phanerogams 269 

Phloem 24,  34,  38 

Phoe.nix  dactylifera 226 

Pholas 314 

Pholas  dactylus 314 

Phosphorus  in  Wood  234 

Phyllosticta  acericola  (fungus) .  .   272 
Physical      Properties,       India- 
rubber 431 

Woods, 18,  26,  33,  237-265 

Physiological  Processes  of  Trees,  8, 

9,  10,  11,  12,  13,  233 
Influence  upon  Properties  of 
Wood,    8,    9,    10,    11,    12, 
233 

Picea 64,65 

alba 64,66,67 

canadensis 67 

engelmanni 64,  68 

excelsa 64 

mariana 66 

nigra 64,  66,  67 

rubens 64,  66 

sitchensis 69 

Piddock 314 

Pieces,  Edge-grained 40 

Quarter-sawn 24,  39,  40,  334 

Rift-grained 40 

Straight-grained 40 

Vertical-grained 40 

Pigment,  in  Wood 17,  37 

Barium  Sulphate  .  .   382,  383,  434 
Bismarck  Brown  . .  .   388 


PAGE 

Pigment,  Bone  Black 384 

Carbon 384 

Chrome  Green  . . 382 

Yellow 382 

Graphite..  .  .' 384 

Iron  Oxide 378,  383 

Ivory  Black 384 

Litharge 383,434 

Paris  White.... 389 

RedLead 383 

Silica 383 

White  Lead 378,382 

Zinc  White 378,  382,  434 

Pignut 146 

Water 248 

Pin,  Knot 43 

Rot 94 

Pine,  3,  5,  30,  43,  44,  45,  49,  65,  67, 
70,  72 

Alaska 79 

American  White 48 

Arizona  Flexilis 49 

Bastard 47,53,55,60,76 

Bhotan 60 

Big 50,56 

Black 55,58 

Black  Norway 58 

Black  Slash 55 

Blister 73 

Brown 52 

Bull 47,  49,  54,  55,  56,  60,  272 

Canadian  Red 57 

Carolina 54 

Common  Yellow 54 

Cornstalk 55 

Cowdie 63 

Cuban. . 46,  47,  53,  261 

Dantzic 45,  59 

Digger 60 

Fat...'. 62 

Finger  Cone 51 

Fir 73 

Florida 52 

Florida  Longleaved 52 

Florida  Yellow 52 

Foothills  Yellow 56 

Foxtail   55 

Frankincense 55 

Georgia  (see  Longleaf  Pine) . 


466 


INDEX 


PAGE 

Pine,  Georgia  Heart 52 

Georgia  Longleaved 52 

Georgia  Pitch 52 

Georgia  Yellow 52 

Gigantic 50 

Ginger 92 

Gray 60 

Grayleaf 60 

Great  Sugar 50 

Hard,45;  46,  47,  52,  54,  57,  58,61,70 

Heart 52 

Heavy 56 

Heavy-wooded 56 

Indian 55 

Jack 60 

Jersey 61 

Kauri 62,  63,  387 

Limber 49 

Limber-twig 49 

Little  Sugar 50,  51 

Loblolly. .  .  .46,  53,  55, 60,  261,  275 

Lodgepole 60,275 

Longleaf,  2,  28,  31,  46,  47,  52,  53, 
261,  275 

Longleaved 56,  58 

Longleaved  Pitch 52 

Longleaved  Yellow 52 

Longschat 55,  58 

Long  Straw 52 

Longstraw 55 

Marsh 60 

Meadow 53,  55,  60 

Mexican  White 46 

Montana  Black 56 

Monterey 60 

Mountain 51 

Mountain  Wey mouth 51 

Murray 60 

North  Carolina 54,  55,  60 

North  Carolina  Pitch 52 

North  Carolina  Yellow 54 

Northern 45,48,59 

Norway 57 

Nut 46 

Old  Field • 54,55 

Oregon 46,47,70,71 

Pacific 70 

Parry's 46 

Patternmaker's  .  48 


PAGE 

Pine,  Pifion 20 

Pitch 47,52,53,54,56,58 

Pond 60 

Poor 54 

Puget  Sound 71 

Pumpkin 48 

Red 56,57,71 

Rigid 58 

Rocky  Mountain 49 

Rocky  Mountain  White 49 

Rosemary 52,  54,  55 

Sabine 60 

Sap 55,58 

Scotch 59 

Scrub 60 

Shade 50 

She 53 

She  Pitch 53 

Shortleaf 46,  47,  54,  55,  261 

Shortleaved  Yellow 54 

Shortshat 54 

Silver 46,51,73 

Slash 53,54,55 

Soft 45,48,51 

Southern 2,52 

Southern  Hard. ......   46,  52,  261 

Southern  Hard  Dense 261 

Southern  Hard  Sound 260 

Southern  Heart 52 

Southern  Pitch 52 

Southern  Yellow 52,  56,  260 

Spruce. .....   47,  48,  53,  54,  55,  60 

Stone. 60 

Sugar 45,46,50 

Swamp 53,  55 

Tamarack 60 

Texas  Longleaved 52 

Texas  Yellow 52 

Torch 55 

Turpentine 52 

Virginia 55 

Virginia  Yellow 54 

Western  Pitch 56 

Western  White 46,  51 

Western  Yellow,  20,  23,  25,  50,  56, 

275 

Weymouth 48 

White,  45,  46,  48,  49,  50,  51,  58, 

59,  64,  68,  171,  246 


INDEX 


467 


PAGE 

Pine,  White  Blister  Rust 48,  50 

Whitebark 46 

Yellow. ...   2,  47,  52,  54,  55,  56,  58 

Yew 66 

Finite 50 

Pinus 45,  65 

albicaulis 46 

caribtea 53 

cembra 60 

cembroides 46 

divaricata 60 

echinata 46,  47,  54 

edulis 20 

excelsa 60 

flexilis 46,49 

glabra 60 

heterophylla 46,47,53 

lambertiana 45,  46,  50 

mitis 54 

monticola 46,  51 

murrayana -.  .  .     60 

palustris,    2,    5,    46,    47,    52,    53, 
246 

ponderosa 20,  23,  25,  56,  272 

quadrifolia 46 

radiata 60 

resinosa 57 

rigida 58 

sabiniana 60 

serotina 60 

strobiformis 46 

strobus 45,  48,  59, 171,  246 

sylvestris 45,  59 

tceda 46,  47,  53,  55 

taxifolia 70 

virginiana 61 

Piquant  Amourette 167 

Pistacia  lentiscus 388 

Pitch 53,54,64 

Tubes 64 

Pith 24,34,37 

Cavity 24,34,37 

Knot 42 

Ray 22,  24,  26,  40,  249 

Ray  Cells 19 

Ray  Primary 24 

Ray  Secondary 24 

Pits 18,  19,  20,  21,  102 

Bordered..  20 


PAGE 

Pits,  Simple 18,  19,  20,  23,  102 

Plane,  American 156 

Common 156 

Oriental 156 

Tree 156,157 

Planks 40 

Plants,  Non-Seedbearing 269 

Seedbearing 4,  269 

Plaqueminier 203 

Platane 157 

Platanus 156 

occidentalis 156,  157,  158,  246 

orientalis 156 

racemosa 156,  158 

Plum,  Date 203 

Gopher 189 

Polished    Wood,     Specification 

for 398,400 

Surfaces,  395,  396,  397,  398,  399, 
400 

;  Polymerization 435 

Polyporus  carneus 86 

Polyporus  juniperus 86 

Poplar 3,  73,  169,  171,  172 

Balsam 169 

Bay 186 

Blue 171 

Carolina 173 

Hickory 171 

Large 172 

Largetooth 172 

Necklace 173 

Tulip 171 

White 171, 172 

Yellow 171,248 

I  Popple 171,172 

I  Populus 169 

balsamifera 73,  169, 174 

deltoides 173 

grandideritata-, 172 

monilifera 173 

tremuloides 169,  172 

trichocarpa 174 

i  Pores 21,  30,  247,  249,  375 

j  Porosity  (Defined) 247 

Wood 37,  237,  247,  248 

Porthetria  dispar 320 

j  Possumwood 203  * 

Potassium  in  Wood . .  .   234 


468 


INDEX 


PAGE 

Powell  Process  (Wood  Preserva- 
tion)    374  ; 

Preference  for  Wood 2   \ 

Preparation  of  Wood  for  Fire 

Coatings 284  ' 

Glue 408  i 

Internal  Preservative  Treat- 
ment      353,  374  i 

Paints,  Oils  and  Varnishes,  284,   j 
402 

Seasoning 328 

Test  Pieces 255,  256   j 

Preservatives,  Wood,  265,  317,  335, 
337,  338,  339,  340,  341,  342,   \ 
343,344,345,346,347,348,   j 
349,  350,  351,  352,  353,  375, 
377,  379,  380,  381 
Pressure,  Influence  upon  Preser- 
vative Treatment.  .  .  .  361 

Prickly  Thatch 227 

Pride  of  India 214 

Primary,  Canal 26 

Pith-Ray 24 

Resin-duct 25 

Wall • 19 

Wood 10 

PrimaVera 207,210 

Principles  of  Fire  Protection,  292, 
293,  294,  295,  296,  297,  298, 
299 

Prionoxystus  robinice 321 

Properties  of  Structural  Mate- 
rials   xvii,  1 

Properties  of  Woods,  Chemical 

Composition,    9,    26,    233, 
234,  235.  281 
due  to  Organic  Origin,  233,  234, 

235 

Physical,  (see  Physical  Prop- 
erties of  Wood},  263,  264,265 
Physiological,    8,    9,    10,    11,    12, 
233 

Special 233 

Prosopis 165 

juliflora 165,  168 

odorata .   165 

Protection  of  Glue 410 

Protection  of  Wood 

Allardyce  Process 371 


PAGE 

Protection  of  Wood 

Bethell  Process 363,  371 

Boiling  Process 372 

Boucherie  Process 372 

Brush  Applications 354 

Burnett  Process 368 

Card  Process 371 

Charring 373 

Creoaire  Process 374 

Creo-resinate  Process 372 

Dipping  Brush  and  Soaking 

Applications 354 

Empty  Cell    Processes,  351,  361, 

362,  369,  370,  371 
External  Treatment,  284,  285,  286, 

315,  377,  378,  389,  390,  391, 
392,  393,  394,  395,  396,  397, 
398,  399,  400,  401,  402 

Ferrell  Process 374 

from  Burning,  282,  283,  284,  285, 
286 

from  Rot 273,  274,  275,  276 

from  Wood  Borers,  309,  310,  313, 
315,316,317,318,320,321, 
322,  323,  324 
Full  Cell  Processes,  351,  361,  362, 

363,  368,  369 

Hasselmann  Process 374 

Hayford  Process 364 

Internal  Treatment,  282,  283,  284, 

317,  318,  335,  336,  337,  351, 
352,  353,  354,  355,  356,  357. 
358,  359,  360,  361,  362,  363, 

364,  365,  366,  367,  368,  369, 
370,    371,   372,   373,   374, 
375 

Kyan  Process 355 

Lowry  Process 370 

Miscellaneous  Processes 373 

Non-pressure  Processes  .  .353,, 355 
Open  Tank  Process,  355,  356,  357, 

358,  359,  360 

Powell  Process 374 

Pressure  Processes.    353,360-373 

Robbins  Process 373 

Ruping  Process  ....   361,  369,  371 

Rutgers  Process 371 

Seasoned    Woods,  266,  276,  334, 

377,  402 


INDEX 


469 


Protection  of  Wood,  Seasoning,  326, 
327,  328,  329,  330,  331,  332, 
333,  334 

Seeley  Process 373 

Superficial  Processes .... 

Thilmany  Process 

Vulcanizing 

Wellhouse  Process 

Woods  that  Respond  to . 

Zinc  Chloride  Process . . . 

Zinc  Creosote  Process . . . 

Zinc  Tannin 

Protoplasm 11,  19,37 

Prunus 202 

serotina 

Pseudophcenix  sargentii 

Pseudotsuga 

douglasii 71 

macrocarpa 

mucronata 1 

taxifolia 47,  71 

Pterocarpus  erinaceus 214 

santalinus 215 

Pterocarya  caucasica 141 

Pullman    Specif.,     Car    Paint- 
ing    400 

Putty 393 

Pyrus  augustifolia 127 

communis 127 

coronaria..  .    127 


PAGE 
326 

Ouercus   obtusiloba 

PAGE 
.  .    109 

332 

palustris       

105,  113 

pedunculata                    .  . 

105,  119 

373 
353 
374 

prinus  
pubescens  
robur                            .      .  . 

105,  108 
...   119 
.  .    105 

373 
371 
374 
368 
371 
371 

robur  intermedia  
robur  var.  pedunculata  .   3, 
robur  var.  sessiliflora  
rubra  3,20,  105,  112, 
sessiliflora  
stellata 

.  ..   119 
104,  119 
104,  119 
150,  246 
105,  119 
.   109 

236 

tinctoria                   

...    115 

202 

triloba 

.    114 

205 

velutina               

105,  115 

225 

virens 

...   116 

70 

virginiana     105, 

116,  246 

71 

wislizeni                      

...    118 

70 
,246 

R 

mains . . 


127 


rivularis. .  .127 


Q 


Quartered  Surfaces .  .  24,  39,  40,  334 

Quartz  Ground,  Pigment 383 

Quercus. 3,21,104 

agrifolia 105  117 

alba 3,  19,  22,  105,  106,  246 

chrysolepis 105,  118 

cuber 246 

digitata 105,  114 

falcata 114 

garryana 105,  111 

lobata Ill 

macrocarpa 110 

michauxii 105,  107 

minor 105,  109 


Racine  Boats 411 

Radial  Surfaces  of  Wood 39 

Railroad  Spikes,  Holding  Power  242 
Railway  Eng.  Assn.  Specif,  for 

Creosote 344,345 

Rainfall 14 

Range  of  Species.  . 16 

Rattan 232 

Ray  Parenchyma 301 

Ray-tracheid 24 

Razor  Clam 301 

Recorders,  Watchmen's 299 

Red  Flower 136 

Red  Lead  Pigment 383 

Redwood,  27,  36,  46,  72,  86,  98,  99, 
100,  101,  208,  275 

California 101 

'Coast 101 

Common 98,  99,  101 

Curly 98 

Giant 101 

Mammoth 98,  99,  101 

Resilience,  Wood 237,  241 

Resin,  2,  4,  17,  25,  26,  44,  45,  46,  47, 
57,  62,  234,  235,  246,  247, 
385,  386,  387,  388,  432 

Amber 385,  386 

Anime 386 


470 


INDEX 


PAGE 

Resin,  Canal  (see  Resin  Ducts) 

Copal 386 

Dammar 385,  387,  388 

Duct  ...  23,  24,  25,  26,  28,  45,  247 

Primary 25 

Secondary 25 

Fossil 62,385,386,387 

Fresh-product 62 

Guajac 191 

Kauri 62,  63,  385,  387,  388 

Mastic 385,388 

Pine 388 

Sandarach 387 

Semi-Fossil 62 

Shellac 387,  392,  397 

Solvents 378,  379,  380,  381 

Varnish. ...   62,  385,  386,  387,  388 

Zanzibar 386 

Resonance  (Denned) 249 

Wood 237,249 

Rhapis  flabelliformis 232 

Rhododendron 195 

maximum 193,  195 

Rift-grained  Pieces 40 

Rigidity  (Denned) 239 

Wood 237,239 

Rings,  Bands,  or  Layers,  Annual,  5, 
6,  10,  11,  29,  30,  34,  35,  36, 
37,  102,  360 

Ring-porous  Woods 30,  31 

Robbins  Process  (Wood  Preser- 
vation)    373 

Robinia 165 

pseudacacia 165,  166,  246 

Roble 210 

Rolled  Lumber 41 

Root,  Diseases 272 

Fungi...' 272 

I\mgous  Diseases 272 

Rot,  Southern 272 

System  of  Tree 8 

Rose  Bay 195 

Rosewood 214 

African 214 

Brazilian 214 

California 215 

Canary 214 

Rosin.. 388,434 

Rot,  Black  Scale 214 


PAGE 

Rot,  Chestnut  Bark 149,  150 

Dry 42,268,  274,401 

Pin 94 

Red 86 

Soft 42 

Wet 42,  268,  274 

White 86,  121 

Wood 268,  273,  274,  275,  276 

Rotary-cut 40 

Rotten  Knot 43 

Round  Knot 43 

Rubber,  (see  Indiarubber). 

Oil 379 

Tree 213,427 

Rueping  Process  (Wood  Preser- 
vation)    361,  369,  371 

Rule,  Density 46,  260 

Rupture,  Modulus  of. .   33,  239,  261 

RustinWood 42,268 

Rutgers  Process  (Wood  Preser- 
vation)     371 


Sabal  mexicana 225,  227 

palmetto 225,  227 

Sabicu 213 

Sagwan 212 

Salix .  .  . 177 

alba 177,  178 

caprea 177 

fluviatilis 177 

fragilis 177 

nigra 178 

russeliana 177 

Sand  Flea 310 

Sandalwood 215 

Oil 380 

Red 215 

Sandarach 387 

Sanderswood 215 

Santalin 215 

Santalum 215 

album 215 

!  Sap,  11,  20,  21,  37,  38,  235,  262,  263 

Circulation  of 11,  20,21 

Crude 11,235 

Effect  upon  Properties,  26,  262,  263 

Elaborated 11,37,235 

Movement..  ...   11,  20,  21 


INDEX 


471 


PAGE 

Saprophytes 269 

Sapwood,  25,  34,  37-,  38,  47, 120,  144, 
246,  247,  262,  351 

SasifraxTree , 199 

Sassafac 199 

Sassafrac 199 

Sassafras 198,199 

Calif  ornian 196 

Sassafras 198 

officinale 199 

sassafras 199 

Satinwood 215 

East  Indian 215 

Savin 87 

Saxifrax 199 

Schcefferiafrutescens 193 

Schinus  molle 213 

terebinthifolius 214 

Scolytidce 319 

Season,  Influence  upon  Cutting,  262, 

263 
Seasoned  Woods,  Protection  of,  266, 

276,  334,  377,  402 

Seasoning  of  Woods,  266,  276,  326, 
327,  328,  329,  330,  331,  332, 
333,  334,  402 

Air 327 

Kiln-drying,  328,    329,   330,   331, 
332,  333,  334 

Natural 327 

Water 327,  328 

Yard  Drying.. 327 

Secondary,  Canals 26 

Pith-ray 24 

Resin-duct 25 

Wall 19 

Wood 10 

Second-growth  Woods 120, 144 

Seedbearing  Plants 269 

Seeley  Process  (Wood  Preserva- 
tion)     373 

Semi-vulcanite 434 

Sequoia,  27,  36,  86,  98,  99,  100,  101 

Sequoia 86,98 

sempervirens 98,  101 

washingtoniana 98,  101 

Shagbark 145 

Shakes  (Defects) 41 

Shapes  of  Trees 12,  13 


PAGE 

Shawneewood 180 

Shellac.   385,  387,  390,  392,  397,  398 

Shellbark 145 

Shinglewood 90 

Ship-painting 399 

Shipworm,  98,  225,  300,  301,  302, 
303,  304,  305,  306,  307,  308, 
309,  310,  311,  312,  313,  314, 
315,  316,  317,  318,  340 

Boring  Shell 303 

Calcareous  Lining 303 

Collar 302,303 

Excavations 307 

Field  of  Attack. 309 

Foot 303 

Form 301 

Influence  of  Temperature  and 

Water 306 

Method  of  Attack 307 

Pallets 302 

Protection  from 315 

Rapidity  of  Work 308 

Reproduction   and   Develop- 
ment     305 

Siphon 302 

Size  of  Borings 308 

Woods,  Subject  to  Attack,309,  310 
Shutters,  Fire.  .  .   284,  285,  295,  296 

Sieve  Tubes 38 

Signals,  Fire 298 

Silica,  Pigment 383 

Silverbell 248 

Silver  Fish 320 

Thatch 227 

Simmon 203 

Simple  Pits 18,  19,  20,  23,  102 

Sipiri 201 

Sissoo 213 

Slab 40 

Slash-cut  Pieces  40 

Slice-cut  Pieces 40 

Smoking  Bean 181 

Soaking  (Preservation  of  Wood)  354 

Soft  Bast 38 

Soft  Rot 42,268 

Softshelled  Clam 301 

Softwoods 4,  6,  30,  43,  44 

Sorbus 126 

americana.  .  .   126 


472 


INDEX 


PAGE 

Sorbus,  sambucifolia 126 

Sound,  Conductivity  of  Wood .  .   248 
Special  Properties  of  Woods . .  .   233 

Sound  Knot 42 

Southern  Creosoting  Co.,  Specif.  364 

Soymida 206 

febrifuga 206 

Spanish  Bayonet 228 

Dagger 228 

Spar  Varnish 386 

Special  Properties  of  Woods .  .  .  233 

Species 3,  16 

Defined 3 

Distribution  of 16 

Number  of 3 

Specifications,  Analysis  of  Creo- 
sote, 346,  347,  348,  349,  350 
Amer.   Railway  Engr.   Assn. 

(Defects) 42 

Amer.    Society    for    Testing 

Materials  (Defects) ...     42 

Application  of  Cattle  Glue,  408, 409 

Application  of  Creosote,  358,  359, 

360,    364,    365,    366,    367, 

368,  370 

Application  of  Fish  Glue.  .  .   414 
Application  of    Paint,    391,  392, 
393,  394,  398,  400 

Automatic  Sprinklers 297 

Car  Painting '. 400 

Creosote,  344,  345,  346,  347,  348, 
349,  350 

Defects  in  Wood 42 

Density    Rule    for    Grading 

Southern  Hard  Pine .  .  260 
Hardwood  Mfrs.  Assn.  of  the 

U.  S.  (Defects) 42 

Open    Tank    Process   (Wood 

Preservation) 358 

Pacific  Coast  Lumber  Mfrs. 

Assn.  (Defects) 42 

Wood  Polishing 398,  400 

Yellow  Pine  M|rs.  Assn.  (De- 
fects)      42 

Zinc  Tannin  Process  (Wood 

Preservation) 371 

Specific  Gravity  of  Wood .  .   237,  244 
Specimens,  Wood  Testing,  252,  255, 
256 


PAGE 

Sphceroma  destructor 314 

Spice-tree 196 

Spike  Knot 43 

Spikes,  Holding  Power 242 

Spiral  (Wood-element)  20 

Spiritine 352 

Spores  Fungi 269 

Spot  in  Foliage 272 

Spring  Deposit 30,  31,  35,  36 

Spring  Wood  (see  Spring  Deposit) . 
Sprinklers,  Automatic,  289,  295,  297, 

298 

Spruce,  28,  29,  43,  44,  46,  64,  65,  66, 
67,  70,  71,  72,  80 

Big  Cone 70 

Black 60,64,66,67 

Blue 66 

Bog 67 

California  Hemlock 79 

Cat 67 

Cork-barked  Douglas 71 

Destroying  Beetle 64 

Double 66,67 

Douglas 47,  64,  70,  71 

Engelmann's 68 

Great  Tideland 69 

He  Balsam 66 

Hemlock 78,80 

Kauri 64 

Menzies 69 

Mountain 68 

Norway 64 

Pine 66 

Prickly 60 

Red 64,66,70 

Single 67,73 

Sitka 69,275 

Skunk 67 

Tideland 69 

Water 66 

Western 69 

White 60,  64,  66,  67,  68,  275 

Stains  for  Wood 388,  398 

Standard,  Knot 43 

Moisture  in  Wood 252 

Star    Shakes     (see    Defects     in 

Wood) 41 

Steam,  Influence  upon  Wood,  361, 
362 


INDEX 


473 


PAGE 

Stinkwood 190 

Stone-borers 314 

Stones,  Building xvii,  277,  295 

Stones  and  Woods,  Comparison',  xxii, 
1,255 

Stores,  Naval 15,  47,  53,  58 

Straight-grained  Pieces 40 

Streamflow 14 

Strength  (Defined) 237 

Strength  of  Wood  Influenced  by 

Moisture 262,264 

Strength  of  Sapwood  and  Heart- 
wood 37 

of  Woods,  33,  37,  237,  238,  239, 
240,  241,  242,  243,  244,  245,  246, 
247,  248,  249,  250,  251,  252, 
253,  254,  255,  256,  257,  258, 
259,  260,  261,  267 

Stringybark 216,  223 

Structure,    Wood     (see      Wood 

Structure) . 
Structures,  Maintenance  of. ...  298 

Suberin 39 

Sugarberry 152 

Sugar  Cane 224 

Sugar  Tree 134 

Sulphur  in  Wood 236 

Sumach 193 

Summer  Deposit 30,  31,  35,  36 

Summerwood  (see  Summer  De- 
posit) . 

Summer-felled  Wood 262,  263 

Sunlight,  Influence  on  Tree. .   12,  13 

Supeira 201 

Superficial      Processes     (Wood 

Preservation) 353 

Surface  Treatment  of  Woods,  284, 
315,  377,  389,  390,  391,  392, 
393,  394,  395,  396,  397,  398, 
399,  400,  401,  402 

Surfaces,  Cross  (Wood) 39 

Quarter-sawn  (Wood)  24,  39,  40, 
334 

Radial  (Wood) 39 

Tangential  (Wood) 39 

Swamps 83,  85,  86 

Cedar - 85 

Cypress 86 

Tamarack 83,  86 


PAGE 

Swietenia 206,  207 

mahagoni 206,  207,  208,  246 

Sycamore,  30,   156,   157,    158,   246, 

248,  275 
California 156,  158 

System,  Central  Office 299 


Tabebuiadonnell-smithii.  .  .  207,  210 

Tacmahac 174 

Tamarack 60,  81,  83,  84 

Red 83 

Swamp 86 

Western 84 

White 83 

Tanbark 2 

Tangential  Surfaces 24,  39 

Tannic  Acid  (see  Tannin). 
Tannin,  37,  203,  234,  235,  337,  338 
Tar  (see  Naval  Stores).. .  46,  47,  316 

Taxodium 95 

distichum 96,  97,  246 

Taxus 92 

bacata 20 

brevifolia 92 

floridana 92 

Teak 211,212 

African....'. 211,212 

Burma *. . .  212 

Indian 212 

Malabar 212 

Tectona 211 

grandis 211,212 

Teek 212 

Telephone  &  Tel.  Co.  Specif,  for 

Creosote 346,347 

Temperatures,  Destructive 293 

Effect  upon  Wood 293,  329 

Teredo,  (see  Shipworm). 

Teredo  Nails 316 

Teredo  dilatata 301 

megotara 301 

navalis 300,  301 

norvegica 301 

thompsoni 301 

Termes  bellicosus 322 

flavipes 322 

lucifugus .  322 


474 


INDEX 


PAGE 

Termites 201,321 

Protection  from 322 

Summarized 323 

Woods  Destroyed  by 322 

Terrestrial  Woodborers,  18,300,  318, 
319,  320,  321,  322,  323,  324, 
325 

Woods   Destroyed  by,   319,   320, 
321,  322,  323,  324 

Woods  Protected  from 324 

Test,  Density 46,  245,  260 

Test  Machine,  Impact 245 

Test-pieces,    Wood   252,    255,    256, 

258,  259 
Tests,  "Fireproof ed  Woods,  "286,  287 

Glues 417,  418,  419,  420 

Woods,  Physical  Properties  of,  33, 
242,243,244,251,252,255, 
256,  257,  258,  259,  261 
Woods,  Natl.  Forest  Service,  33, 

258,  261 

Woods,  U.  S.  Census,  33,  257,  261 
Woods,  Watertown  Arsenal .  .     33 

Tewart 222 

Thickness-growth  of  Trees.  . .    10,  12 
Thilmany  Process  (Wood  Pres- 
ervation)     374 

Thorn 167 

Thorny  Locust 167 

Thrinaxmicrocarpa 225,  227 

parviflora 225,227 

Thuya 85 

gigantea 86,  90 

occidental 86,89 

plicata 90 

Thysanura 319 

Tidy  Specif,  for  Creosote 344 

Tiel 170 

Tieltree.  .  .170 


americana  
heterophylla  
Timber  (Defined) 

..    170,176 
176 
17 

Tooart 

222 

Toothache  Trees  
Top-soil  
Influence  upon  Rot  .  .  . 
Torchwood 

126 
13,  14 
275 
21 

Torus  

.  ...   18,20 

PAGE 

Toxylon 202 

pomiferum 202,  204 

Tracheae  (Wood  Elements) ....     21 
Tracheal-tubes      (Wood      Ele- 
ments)       21 

Tracheid  (Wood  Elements),  11,  19, 
20,  22,  23,  24,  25,  30,  44, 

102,  247 

Tree  (Defined) 8 

of  Heaven 172 

Yucca 229 

Trees  and  Woods,  Banded  (see 

Trunks  and  Woods,  Banded). 
Broadleaf,  4,  5,  6,  29,  43,  44,  102, 

103,  169,  333 
Coniferous,  4,  5,  6,  20,  29,  43,  44, 

102 

Deciduous 4,  6,  43,  103 

Dicotyledonous,  4,  5,  6,  30,  34,  43, 

102,  169 

Evergreen.  4,  5,  6,  20,  34,  43,  44, 
102 

Hardwood 4,  6,  43,  102 

Identification  of,  17,  27,  28,  29,  30, 

31,  32,  36 
Monocotyledonous,  4,  5,  6,  7,  224, 

230 

Needleleaf,  4,  5,  6,  20,  29,  36,  43, 
44,  102 

Non-banded 6,  9,  29,  224 

Softwoods 4,  6,  43,  44 

Trees,  Forms  of 12,  13 

Fungous  Diseases 271 

Influence  of  Sunlight 12,  13 

Inside-growing 6,  7,  9,  224 

Leaf  Systems  of 9 

Length-growth  of 9 

Number  of 3 

Outside-growth  of,  5,  6,  9.  29,  30, 

34,43,44,  102,169,224 
Physiology  of,  8,  9,  10,  11,  12,  13 

Root  System  of 8 

Shapes  of 12,13 

Thickness-growth  of 10,  12 

Trunk  System  of 9 

Trichophyton     tonsurans     (fun- 
gus)     270 

Trunks 9,16,34 

Fungous  Diseases  of 272 


INDEX 


475 


PAGE 

Trunks  and  Woods,  Banded,  5,  9,  29, 

30,  34,  43,  44,  102,  169,  224 

Non-banded 6,  9,  29,  224 

Tsuga 65,  78 

canadensis 80 

caroliniana 80 

heterophylla 78 

mertensiana 78,  79 

Tuart 216,222 

Tubes  (see  Wood  Elements] 21 

Pitch 64 

Sieve 38 

Tulip 102 

Tulip-tree 169, 171, 175 

Tung  Oil 214,  379,  380 

Tree 214 

Tupelo 189,190,275 

Large 189 

Sour 189 

Swamp 189 

Turpentine,  2,  25,  46,  47,  53,  54,  57, 

60,  62,  381,  399,  435 
Venice 62,82 

Xyloses 21,  247,  248,  375 

U 


Ulmus 

alata 

americana 

fulva 


....  128 
....  132 
....  129 
..  3,131 

pubescens 129,  131 

racemosa 130 

thomasi 130 

Umbellularia  calif ornica. .  .    195,  196 

Umbrella  Tree 214  ; 

Unbled  Woods 46,47   j 

United  States  Census,   Exper.,   33,   ! 
257,  261 

Unknown  Tree 152   j 

Use,  Wood  Destroyed  by 266 

Uses  of  Wood. .  2 


Variety  (Botanical) 3 

Varnish,  xviii,  377,  378,  379,  385,  386, 

387,  388,  395,  396 
Application  of,  395,  396,  397,  398, 

399 
Japan 380,381 


PAGE 

Varnish,  Oil 62,  378,  385 

Resins 62,  385,  386,  387 

Spar 386 

Spirit 62,378,385 

Woods  to  Receive 402 

Varnishes,  Oils,  and  Paints ....  377 

Vasa 21 

Veneer 40,  414,  415,  416,  417 

Veneers,  Rotary  Cut 169 

Veneered  Work,  Appearance  of .   417 

Economy  of 417 

Preparation  of 416 

Stability  of 417 

Uses  of 414 

Venice  Turpentine 62,  82 

Vertical  Grain  in  Woods 26 

Grain  Pieces 40 

Vessels,  19,  21,  28,  30,  44,  247,  375 

Vessel-segments 21 

Vitse 29 

Vitality  of  Wood 267 

Vulcanite 434 

Vulcanite-semi 434 

Vulcanization,  Ihdiarubber,  430,  431, 

434 

Vulcanization  (Wood  Preserva- 
tion)  373,430,431,434 

Vulcanized  Rubber.. .  .   430,  431,  434 


W 


Wahoo 132 

Wain 40 

Wall   (Wood  Element) 19 

Walls,  Primary 19 

Secondary 19 

Walnut,  3,  19,  21,  22,  139,  142,  143, 
144,  145 

American 140 

Arizona 140 

Austrian 141 

Black,  19,  21,  22,  23,  30,  139,  140, 
142,  188,  248 

California 140 

Caucasian 141 

Circassian 139,  141,  186,  215 

Dwarf 140 

English 139,141,209 

European 139,  141 


476 


INDEX 


PAGE 

Walnut,  French 141 

Italian 141 

Little 140 

Mexican 140 

Oil ; 379 

Persian 141 

Royal 139,  141 

Russian 141 

Satin 141,  186,188 

Shagbark 145 

Sweet 145 

Turkish 141 

Western 140 

West  Indian 141 

White 139,140,143,210 

Washingtonia  filifera 225,  226 

Watchman's  Recorders 299 

Water  in  Wood,  17,  26,  234,  237,  245, 
246,  252,  258,  262,  263,  264, 
265,  329 

Paints 389 

Seasoning  of  Wood 327,  328 

Waterglass,  Paint 285,  401 

Watertown      Arsenal      Experi- 
ments    33,257,261 

Weathering  of  Woods 267 

Weights  of  Woods,  18,  33,  237,  244, 

245,  246,  247,  261,  267 
Weights  and  Moduli  for  Woods 

(Summaries) 33,  261 

Wellhouse  Process  (Wood  Pres- 
ervation)    371 

Wet  Rot  in  Wood 42,  268,  274 

Whahoo 132 

White,  Ant  (see  Termite) 

Lead  Pigment 378,  382 

Pine  Blister  Rust 48,50 

Whitewash 389 

Whitewood  ...   46,  169,  171,  173,  176 

Whiting 389 

Wickup .    176 

Wild  Date 254 

Willow 177,  178,213 

Basket 177 

Bedford 177 

Black 178 

Crack 177 

Desert 248 

Goat..  .    177 


PAGE 

Willow,  Longleaf 177 

Osier 177 

Sandbar , 177 

Swamp 178 

White 177,178 

Windfalls 65,  121 

Windows,  Fireproof 296 

Wind  Shakes  in  Wood  (Defects),  41, 
333 

Winter  Felled  Wood 262,  263 

Wired  Glass. 296.  297 

Wood,  Banded,  5,  6,  9,  29,  30,  34,  43, 
44,  102,  169,  224 

Bled 46,47 

Broadleaf,  4,  5,  6,  29,  36,  43,  44, 

102,  103,  169,  333 
Cells  (see  Wood  Elements). 
Chemical  Composition  of,  9,   13, 
26,  37,  38,  39,  233,  234,  235, 
236,  237,  281 
Coloring  Matter  in,  17 
Coniferous,  4,  5,  6,  26,  29,  30,  34, 
36,  43,  44,  102,  103 

Consumption  of 1,  2 

Deciduous 4,  6,  43,  103 

Defects  in 40,  41,  42,  43,  333 

Defined 17 

Density  of 237,244 

Destroyed,  by  Age 266,  267 

by  Ants ,   321,323,324 

by  Bees 323 

by  Beetles 319,320 

by  Chelura 313 

by  Decay  (see  Decay  in  Woods) . 

by  Exposure 267 

by  Fire,  277,  280,  281,  282,  283, 

284,  285,  286 

byLimnoria..  310,311,312,313 
by     Miscellaneous     Wood- 
borers 314 

by    Moths  andButterflies,  320, 

321 

by  Shipworms,  225,  300,  307, 
308,  309,  310,  315,  316,  317, 
318 

by  Termites 321,  322,  323 

by  Use 267 

Dicotyledonous,  4,  5,  6,  30,  34,  36, 
43,102,169 


INDEX 


477 


PAGE 

Wood.  Diffuse-porous 30,  31 

Durable 266,  274,  275,  276 

Elements,  11,  17,  18,  19,  20,  21,  22, 
23,  24,  25,  26,  27,  28,  29,  30, 
31,  34,  38,  39,  44,  45,  102, 
224,  225,  237,  247,  248,  249, 
252,  375 

Evergreen 4,  6,  43,  44,  81 

First-growth 120 

Flea 310 

Hard  (see  Broadleaf  Woods). 

Heart 25,  34,  37,  247,  351 

Hygroscopicity 251 

Identification  of 17,  27,  32,  36 

Importance  of....xvii,  xviii,       1 
Monocotyledonous,  4, 5,  7, 224, 230 
Needleleaf     (see     Coniferous 
Woods). 

Nomenclature 2,  47 

Non-Banded 6,  9,  29,224 

Non-Durable   (see  Perishable 

Woods). 

Non-Coniferous  (see  Broadleaf 
Woods). 

Non-Porous 30,  31 

Parenchyma 24,  30 

Physical  Properties  of,  18,  26,  33, 
237,  251-265 

Porous 30,  31,  37 

Prepared  for  Fire  Coatings .  .  .   284 

for  Glue..  . 408 

for    Internal    Preservative 

Treatment 353,  374 

for  Paints  and  Other  Coat- 
ings    284,402 

for  Seasoning '. 328 

for  Test  Pieces 255,  256 

Preservatives    (see    Preserva- 
tives of  Wood). 

Primary 10 

Protected  from  Burning,  282,  283, 

284,  285,  286 

from  Rot. . .  .   273,  274.  275,  276 

from  Woodborers,  309,  310,  313, 

315,  316,  317,  318,  320,  321, 

322,  323,  324 

Wood,  Sapwood,  25,  34,  37,  38,  47, 


120, 
351 


144,    246,    247,    262, 


PAGE 

Wood,  Secondary 10,  19 

Second-growth 120,  144 

Soft 4,  6,  20,  30,  38,  43,  44 

Special  Properties  of 233 

Spring 35 

Summer 35 

Vitality  of 267 

Woodborers,  Land,  .300,  318,  319, 
320,  321,  322,  323,  324.  325 
Marine,  95,  225,  300,  301,  302,  303, 
304,  305,  306,  307,  308,  309, 
310,  31.1,  312,  313,  314,  315, 
316,  317,  318,  340 

Miscellaneous 314 

Protection  from,  315,  316,  317, 
318,  320,  321,  322,  323,  324, 
325 

Woods  and  Trees  (see  Trees  and 
Woods). 

Wool,  Cotton 234 

Worm,  Carpenter 321 

Nails 316 

X 

Xanthoxylum  americana 126 

clava-herculis 126 

cribrosum 215 

Xylem 24,34 

Xylocopa  virginica 323 

Xylophaga  dorsalis 301 

Xylotrya 300 

fimbriata 301,  305,  306 


Yearly  Bands,  Rings,  or  Layers 
(see  Annual  Rings, 
Bands  or  Layers). 

Yellow  Bark 121 

Yellow  Pine  Mfrs.  Asso.  Specif. .     42 

Yellow-wood 193,  204,  205 

Yew 20,  92 

California . 92 

Florida 92 

Oregon .- 92 

Western 92 

Yucca 224,  228,  229 

Aloe-leaf .  .  .228 


478 


INDEX 


PAGE 

Yucca,  Breadfruit 228 

Cactus 229 

Mohave 228 

Schott 228 

Tree 229 

Yucca 228 

aloifolia 228 

arborescens 228,  229 

brevifolia 228,  229 

constricta 228 

gloriosa 228 


PAGE 

Yiicca,  macrocarpa 228 

mohceuensis 228 

treculeana 228 

Z 

Zanzibar 386 

Zinc  Chloride  Processes 368,  371 

Creosote  Process 371 

Oxide 382,  434 

Tannin  Process  Specif 371 

White  Pigment 378,  382,  434 


REC'D  Lt 

OCT8    '64.5 


TA.4      .   3C5844 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


